Posts tagged voicing
I had the full intention of writing a blog on piano voicing and then suddenly realized that there are 3 completely valid meanings to piano voicing. The first meaning of voicing refers to chord voicing which denotes how you spread out the notes of a chord on the piano (quite often in the jazz idiom). The second meaning, as it refers to piano playing and pedagogy means making the melody line stand above the accompaniment. You voice the melody to be more audible than the rest of the notes you’re playing. The third definition however, refers to the technical aspect of manipulating the tone of the piano. It is this subject I’d like to delve into a little deeper.
When I was young I was slightly misguided in thinking that every piano brand had a signature sound. While there is truth in that statement, pianos can sound vastly different from model to model and can vary from even piano to piano. Why? At the core, the piano is comprised of natural products such as wood, felt, steel, leather and iron. All of these raw materials have anomalies and subsequently, no 2 pianos are the same. So while it is true that there are inherent qualities of tone related to a brand, the subtleties vary significantly from piano to piano. Voicing serves 2 purposes: one is to alter and change the global sound of a piano and two, to make a piano sound even.
What does it mean to have “even” tone? When I was 13, my piano teacher asked me to play a scale. “Play it like a string of pearls ~ matched in color and size. If you want to get louder, do so by tapering each note a little louder, then a little softer. Do everything gradually.” It was an idea that I could visualize where each pearl had its own quality and it was up to me as a performer to use some sense of skill to match one note on the piano to the neighbouring note. She taught me a lot about making simple technique musical. And when you play notes on the piano evenly in succession, it tricks our ears into thinking it’s monophonic (meaning “one sound” like the human voice).
At times, however, I’ll be playing what I believe to be consistently when all of a sudden, one note sounds different than the rest. Playing the note in isolation, it becomes apparent that this one note sounds sharper or “brassy”, bright or strident while the neighbouring notes sound warmer, mellower or darker. These are common words many people use to describe the tone of a piano. In short, the fix for the protruding note is called piano voicing. Piano voicing involves manipulating the instrument to achieve a different audible result. To create an even performance at the piano, it must be voiced so that each note sounds similar to its neighbours, making transitions in a musical line seamless. When I was in Hailun and Petrof factories last year, I took some time to watch factory workers whose jobs are solely voicing and tuning. It takes a trained ear and substantial skill to play notes quickly in succession and level the audible high spots which are strident and bring up the low notes to match the others.
So how does this process happen? How does one change the sound of a piano? To answer that, we need to think of what parts can be altered readily on a piano? Voicing predominantly involves altering the strike point of the hammer as it touches the strings. Yes, it could involve many other procedures but voicing is more commonly referred to as an immediate alteration to the wool hammers to produce a different tone. As to how this art of voicing happens, preparation precedes practice.
Pianos must first be in tune. How do you listen to the nuances of tone if the strings are not in unison? When you look inside a piano, 2/3rds of the notes have 3 strings per note. See our recent blog entitled How Often Should I Tune My Piano for a full description of the strings inside a piano. If there are 3 strings on a single note and they each are resonating at different frequencies, it’s like having 3 people talking at the same time. It’s impossible to hear the tonal quality of a note when all of the strings are not resounding in unison. So the first step leading to voicing is tuning. It is also during this time that most piano technicians make mental notes of the “worst offenders” which are anomalies across the keyboard. Because tuning takes well over an hour to get it in shape, familiarity with the piano also happens during this time. It takes time with a piano to find out what sounds it produces ~ what are its strengths and weaknesses and what areas need addressing more than others.
Levelling the playing field
Seating: At times, some notes will give off distortion. A trained technician will know that this is sometimes caused from the string not sitting flush up against termination points. Moving the string slightly can alter a note drastically.
Centering: Over time, some hammers shift from their strike position and don’t hit the all of the strings squarely. Adjusting the hammers to be striking in the center of the felt and at the same time is extremely important to consistent tone.
Travel refers to the movement of the hammer up towards the string. If the hammer is on an incorrect trajectory towards the string, it will hit the strings at more of an angle and also create odd tones or have one string strike before the other two. “Squaring” the hammers ensures they strike in the correct position at the same time.
Surface Preparation: If grooves in the hammers are significant, filing the felt of the hammers should be done to regain proper surface contact.
Action Corrections: Sometimes one note will be misbehaving mechanically and render it powerless. In such cases, it tricks our ears into thinking it has a different tone when in fact, there’s a mechanical problem. There are many issues that can arise in a piano that lead us to believe individual notes need voicing when in fact they require mechanical fixes or adjustments.
With the aforementioned areas addressed, voicing can now commence. Please note: these are piano BASICS. Pianos are much more involved but for the purpose of describing piano voicing, these are the baselines which all pianos must adhere to. These are the practical fundamentals of most household instruments and not concert level pianos which can sometimes take days to tweak.
So let me ask, what kind of tone do you wish to have coming from your piano? Beauty, after all, is in the eye of the beholder. Some wish for a power piano – strong and bright. Others want soft and felty. Personally, I look for versatility in a piano. I prefer pianos to be intimate and warm at softer dynamic levels and have a crossover where they can shift into more strident sounds when playing with force. Pianos that are icy cold or brittle at softer volumes I find somehow less satisfying and difficult to express emotionally. Conversely, playing powerful music with a dull thud also feels like it is somehow lacking.
Let’s be clear, however that piano voicing has limitations. I’ve often said that 50% of the tone of a piano is inherent to the instrument. It’s the wood ~ the soundboard, the bridges, it’s the design ~ the scale, the placement and thickness of the soundboard, the amount of ribs, backposts, rim construction etc., it’s the action ~ how it translates our musical intention into sound – all of these elements make up the piano. These I would mainly consider non-negotiable. Yes you can start down the path of reconstructing parts but this is more major surgery. The other 50% can be altered somewhat depending on the quality of the piano and the results vary drastically. Piano hammers also have a shelf life as well. Really old and “dead” sounding hammers fibers, ones that are really grooved, hardened or lifeless sounding need replacement.
Most pianos with time and playing become more brittle and harsh. The majority of the requests for voicing involve making pianos softer with fuller body. When I was young, I sought the brassy power piano. As I age, I look for tonal color more akin to “autumn leaves” ~ colourful, warm and beautiful. We get used to the piano we play and don’t consider that alterations could make the experience more enjoyable. With harsher tones, piano hammers can be “needled” in various locations to achieve those results. A needling tool simply has needles that get inserted into the piano hammer. Since piano hammers consist of felt stretched and glued around a wooden hammer molding, the insertion of the needle “fluffs” hammer felt, making it not so compacted. In other areas of the hammer head, the needle acts to give greater body or sustain. Most piano technicians know how to needle to create the desired effect.
Solutions for both hardening and softening also exist. A hardener coats the hammer and creates more brilliance in tone. Softeners penetrate and relax fibers and create softer sounds. While there are those who disagree with putting anything on the hammers, I believe that there is a place for more drastic alterations of hammers that have desirable end results. The danger is that solutions can be added to a hammer but cannot be extracted. I’ve actually played pianos rendered unplayable due to excessive chemical applications. The recourse really is only to change the hammers. But I’ve also played many pianos that have been strategically voiced with solutions for incredible results. The word here is caution and work with a piano technician you trust. Ideally, I like the felt of the hammer to speak. If you’re looking for a certain sound, sometimes changing the hammer is a better way than to try and artificially transform a piano into something it wasn’t intended to be.
Pianos are dynamic in nature. They are constantly changing. Voicing is not a do-once application but rather a process with time and maintenance. It involves keeping the piano at its best throughout its life-span. Have you lost the love of your piano? Sometimes pianos simply need to be voiced to bring it back to more of the sound when you first acquired it. You’ll be amazed at the results. Piano maintenance is so much more than tuning. Once you realize the possibilities, you’ll be amazed at how musical and beautiful your piano can be. Click HERE for a list of piano technicians in your area.
Three weeks ago I was in a discussion with Basilios Strmec of Vienna International (North American distributers for Hailun, Petrof & Sauter) regarding the creation of virtual piano factory tours on Piano Price Point.
After a slight pause his first response was, “Glen, how flexible are you?”
“Pertaining to what exactly?” was my reply not having any clue where he was headed.
“I’m leaving for China in 10 days and if you can clear your schedule, I’d like to invite you to Hailun Piano Company to do your first tour”.
Knowing I was planning a trip to Toronto for that week I said “Let me call you within 24 hours”. I managed to shuffle some dates to make this happen as I deemed it an exciting new adventure and opportunity.
With new-to-me technology of panoramic photography I started to explain to Basilios during the shuttle from Shanghai what it is I hope to achieve. “I want to bring the masses to the factory” I said, knowing that it is an impossibility in reality but plausible with virtual technology. “I would like to give people the opportunity to look around – to see the stuff of every day life – to see the sawdust and the chisel shavings, to see the rough cast iron frames before they get sprayed beautifully in gold, silver and rose. I’d like consumers to begin with lumber and iron, leather, cloth and felt and end with a finished product ~ to show from inception to creation this process of making the piano.” OK I wasn’t quite that poetic but… you get the point.
In usual enthusiastic manner Basilios replied “Well let’s make this happen! Hailun is transparent and I’d like you to feel at home – to photograph and walk around as you would like.” It wasn’t until I started shooting panoramic images that his eyes lit up. “Wow this is fantastic! It really shows the factory as if you’re standing right here.” That was my intention precisely. The new chapter called Piano Factory Tours is in editing stage and will be released August 2015.
5 Days Later
Debriefing this whirlwind, it’s simply overwhelming the stature and size of the Hailun Piano Company. They manufacture roughly 38,000 pianos per year. Now if you do the math, that’s just over 3,150 pianos per month in 4.2 MILLION square feet of factory space. The construction of the piano is divided up into stations where each employee is trained in specific tasks. Some work on tone wood – the sound producing elements of bridges and soundboards while others work on action parts and how the piano plays. Some produce beautiful finishes and others are involved in the construction of the frames. At the end of the assembly there are usually at least 3 levels of refinement ~ rough tuning and regulation (making all the parts function evenly), then 2nd tuning and voicing (making all of the notes sound consistent) and then 3rd regulation and tuning. All pianos are inspected along the way at various levels. Oh and when you walk into the factory, the sounds – you can’t even begin to describe this one machine – up until this point I had only seen pictures – The piano gets sent into an extremely well insulated booth where this machine strikes the keys to ‘break in’ the piano. The sound of all 88 keys hitting in rapid succession settles the entire piano; the tuning of the strings settle, the hammers find their strike point and the tone begins to really blossom and not sound so ‘green’. All pianos roll through the factory on what look like train tracks. They move from one section or station to another. There are some areas in the factory with tools not dissimilar to my own wood shop having the reminiscent smell of sawdust and conversely, there are multimillion dollar polishing machines working with exacting precision to achieve that mirror gloss many refer to as “piano black finish” or ebony polish. In order to create a piano however, it’s not simply the sum of the parts – it’s the design team of piano visionaries and engineers working at computers and CNC machines (computerized cutting tools precisely notch and cut down to 1/1000th of an inch). It’s also logistics – transporting parts from one area to another and not get bottle necked at any stage along the way. Imagine if there would be a problem in one section, pianos would just start piling up at over 100 per day! So the entire process needs to flow from one section to another. And don’t forget about packaging – the creation of boxes, pallets and air tight packaging. At the helm of this giant ship is Mr. Hailun Chen – an absolute larger than life personality who despite cultural and language barriers makes everyone feel welcome. The few interactions over dinner and meetings, there were great laughs but you also recognize that he’s a remarkable leader who would be first to tell you that it takes a team to build a piano. Hah… and I thought my 5 day trip to China was a whirlwind – try building an entire line of pianos, manufacturing facilities, installing giant machinery, with hundreds of workers, an entire sales force with global presence, achieving publically traded stock status all in just 15 years. Wow.
Special thanks Mr. Hailun Chen & Basilios Strmec (Vienna Piano) and the entire staff at Hailun Piano for accommodating this photo shoot and for facilitating and sponsoring this entire trip from start to finish. Thank you so much for the tour – halfway around the world and back within 5 days. Cheers to Hailun Piano and may you see continued success and growth in the coming years.
Oh and one last thing… in between meetings, I had the opportunity to sit at a Hailun grand piano ~ model 218 (7’3” long) in a performance venue built within the factory. (You’ll be able to see it on the virtual tour). It was lovely not only to catch my breath for a moment but to also sit at this FANTASTIC piano and remember that it’s the inspiration of music that moves mankind to create and build instruments of beauty for the indulgent purpose of expressing what our hearts feel.
I have to admit, I’m a duck to water when it comes to playing the piano. If I see a piano, I’m always curious as to how it sounds and plays. Recently someone said to me “y’know you really should do a blog about how to test pianos… I don’t have the slightest clue how to go about that”. It’s one thing I do instinctively and it made me stop and think about my procedure.
Going back just over 20 years, I was a new upstart that just got hired by the local piano store. With 2 Classical degrees behind me I felt confident I knew my way around the keyboard. Fortunately my boss at the time – now a designer and consultant for Samick Music Corporation put me in my place. I’ll never forget his words “Glen” he stated, “for years you’ve played the piano but don’t presume that you know how the piano works. You’re a race car driver but don’t make the mistake in thinking you’re a mechanic. Drivers are not mechanics”. Thankfully I had enough sense at the time to heed his words.
Over the years, I’ve literally played thousands of pianos. I must say that now knowing cause and effect – what mechanical processes and components creates a certain touch or tone – is a huge asset. And so I’ve compiled my thoughts from the ‘front end’ – from the keyboard side to try and explain a little of what is going on ‘under the hood’ and what tests are fundamental to any piano. I’ve reduced these to 5 steps for newbies (I know… I know… it’s what my kids call me… “Dad you’re such a noob”)
1. Sustain – A piano that sings speaks to its ability to sustain the tone and not disappear after a few short seconds. One thing that I listen for is a piano that sings. Sustain, means that when you depress a key the tone continues to resonate. This sustain speaks to great manufacturing techniques and great components.
Test: Play any note on the piano with medium pressure and listen to the sound as it gradually dies away. How long did it take? What was the sound like as it decays? Carefully listen to low and high notes doing the same. In every octave (every 8 white notes) you’ll hear differences of the ‘decay’ (don’t worry… it’s not the same as tooth decay. It’s the more technical term of ADSR – Attack Decay Sustain Release)
Technical: The strings resonate with just the correct amount of pressure (called down-bearing) onto the bridge where the vibrations are transferred to the amplifier we know as the soundboard. Working properly, the materials should not be ‘inhibiting’ the tone from freely singing. The piano is a transducer, converting the energy of touch to string vibrations and then into sound waves. All three of these elements must be working in sync to produce tone. A piano that sings – that’s a thing of beauty. I’ve played many a piano that has a ‘sweet spot’ in a certain range or octave but to get a piano to sustain from top to bottom, that requires excellence in manufacturing and design. While a good technician can alter some elements of the piano to bring out tone, sustain is a tough one that in my mind either ‘you got it or you don’t’.
2. Evenness – My piano teacher (when I was 13) asked me to play a scale “like a string of pearls – each one should be matched in color and size”. That’s a great lesson in musicality but also for testing pianos. What happens though when you apply the same amount of pressure but neighboring notes don’t respond the same way on the piano? It’s REALLY difficult to express a melody when the piano parts are not manufactured or prepped so that all 88 notes respond with evenness. Often notes ‘jump out’ at you – either in volume or brilliance.
Test: Play a series of adjacent notes with even pressure and see if the volume or brilliance changes. Quite often it is better to strike each note with the same finger if you’re not accomplished at the piano. People unversed with piano technique will unknowingly play heavily with a thumb or finger and think it’s the piano not responding correctly.
Technical: There are approximately 6,000 parts in a piano action. The action is the ‘engine under the hood’. When pianos don’t respond evenly, this could be one of many adjustments (also called regulation). I’ve played pianos that once regulated, you wouldn’t know they’re the same instrument. In addition to adjustments, too much friction, not enough friction, action design, quality of parts, execution in manufacturing, balanced keys – all of these play a part in making all 88 keys function to make the piano play smoothly.
3. Control – Aside from evenness, there is an aspect called control. This is by far the most difficult aspect to explain and most difficult to test. While evenness speaks to neighbouring note difference, control refers to the feel of the keys moving through varying degrees of pressure. This is not referring to the sound of the piano but rather the correlation of key pressure sensitivity to piano tone. What you’re wanting is a piano where the keys feel like an ‘extension of your fingers’. I’ve played many pianos that feel hard to control. This refers to the subtleties of touch. For example, sometimes you’ll be trying to play quietly but the keys feel inordinately heavy and when the tone comes out, it’s not the whisper you’re looking for. At other times you’re looking for power but the piano doesn’t deliver. Making your softs soft and your louds loud – control is vital to satisfaction.
Test: Test one key at a time. First depress a key in slow motion so that the note makes no sound: pay attention to how the key feels. Does it feel succinct at the beginning stage? Does it feel loose or does it feel heavy at the top? How about halfway through the key stroke? Can you feel more pressure? And the ‘click’ at the end of the key stroke – every piano has one – that’s the reset of the key. And finally the cushion of the felt at the bottom – is it too spongy or hard? Play the same note repeatedly getting louder all the while paying attention to the feel. At maximum pressure, how does it feel? The best test for this is to A/B compare different pianos in this process and determine which one feels most ‘natural’. I’ve often said that everyone should play a concert grand at some point in their lives. The most expensive grand pianos usually have been given the most attention at the factory. Sometimes it’s great to get a reference point of a piano that you may not be able to afford… but to try it to see what excellence feels like. Then… reality check – match your budget with the closest piano you can afford. If you’re new to the piano, test the best benchmark you can find.
Technical: Intrinsic to piano design is the geometry of the action. Action design – the weight of a hammer, the degree of the whippen, the placement of the capston, and the quality of all of these parts – all of these small seemingly insignificant parts play a vital role when we attempt to control the piano through varying degrees of pressure.
4. Tonal quality – This refers to the sound of a piano. I’ve played many pianos that excel at one certain volume level but sound terrible at another. Myself? I look for versatility. Ideally I want that really felty soft tone when playing quietly and a more bold strident sound at louder volumes. What do you like? This is by far the most significant element where personal taste is involved. If, for example, the piano sounds great at soft volumes and you only intend to play quietly you may want to look for a piano that suits your ears in more of the quiet range. Some people only play loud and louder and look for a more percussive sound. Different folks, different strokes.
Test: Depress keys one at a time and listen for the color spectrum going from soft to loud playing. Does it change or does it sound the same from soft to loud playing? Does the piano excel at one volume level but not another? Sometimes a piano may seem dull at louder volumes or too bright when playing softly. The harmonics (in plain speak the “ring” or overtones) are at times clanging or distorted. Does the depth of tone feel satisfying in the bass (lowest notes) and do the highest notes (top octave) sound defined or too ‘plinky’.
Technical: As we heard in the interview with Jack Brand, resiliency and elasticity of the hammer felt are vital for the production of great piano tone. The design or ‘scale’ of the strings also plays an important part. In fact, this topic is so immense, we could discuss piano tone all day – the composition or the soundboard, the bridges, the cast iron, the placement of the hammers… the list goes on and on. The main thing is that you actually enjoy the piano you are playing. BTW, often overlooked is simply TUNING the piano! Pianos in tune or out of tune sound vastly different.
5. Touch weight – Do you know how much a nickel weighs? Most piano technicians do. Why? Because touch weight refers to the amount of weight required to set a piano hammer in motion. If the keys feel too heavy, even by the weight of a nickel a piano can often feel laborious or tough to play. (A nickel weighs approximately 5 grams and technicians will use them in a pinch for measuring key weight). But there are in fact two measurements for piano weight – static and rotational inertia. Soft playing ‘dead lifts’ the hammers while loud playing deals more with the inertia of the hammer once set in motion on a rotating axis. Sound complicated? LOL it is!! I’ve had many people ask if something can be done with the touch. The answer is yes but… it’s also complicated and costly to implement. More often than not I advise people to find a piano where the touch feels comfortable.
Test: Play a song or various keys and make mental note to the actual resistance to your fingers. This should feel comfortable. Try and remove your ears for a moment. You’re now not supposed to be listening but feeling. Too light of an action doesn’t provide proper dynamic expression while too heavy can feel tiresome.
Technically: If you look at the wooden edges of the piano keys, you’ll most likely be able to see circles of inserted lead. These weights are inserted into the keys to offset the weight of the hammers and assist in playing at quiet volumes. The weight of the hammer itself however is responsible for most of the rotational inertia at loud volumes. Pianos can play incredibly different at polarized extremes and sufficient testing should be done at different dynamic levels.
So you’ve narrowed down which piano you like? You may want to confirm your decision with a professional. Remember, drivers are not mechanics. Have a word with a local technician. For a list of local technicians in your area, see our Find-A-Tuner chapter.
I’ve often thought that it’s a shame that the new starting point for children has moved away from the piano to an electronic keyboard. We don’t ever fall in love with keyboard sound or touch. I truly believe that kids today quit piano before even being introduced to a real instrument. I remember once having a discussion with someone who had come to my house remarking that they had never seen a grand piano in a home before. They’d seen pictures on TV of grand pianos on stage but never actually come across one in real life. That was amazing to me. I hope that if you’re a newbie at the piano and you read this that you’ll take courage enough to go to a piano store and try one. You’ll be amazed at what you find. These electronic devices we call keyboards are not even a shadow of the depth and beauty of real piano tone. It’s like handing someone a box of crayons and saying “paint a masterpiece”… it simply can’t be done. The depth and richness of shading and color that can be achieved from a real piano that is properly tuned, voiced and regulated is not only a dream to play but allows full expression of tone that goes beyond words. As the great Bill Evans put it, “When you play music you discover a part of yourself that you never knew existed.”
Is he a spy? No. Is he famous? No. But this one man’s company has single-handedly infiltrated most of the major names of pianos in the world. 200,000 pianos per year to be exact! Who is he? Jack Brand. Haven’t heard of him? I hadn’t either until the interview with Del Fandrich a few months back. After some preliminary investigating, I found out that Jack Brand owns a company in Canada called Brand Felt. So what does this have to do with pianos? Jack Brand, third generation felt maker along with his father, Klaus Brand, re-established the German Weickert/Wurzen production facility, the oldest, most respected felt maker of piano felt in the world. I queried Jack a few months ago about his interest in shedding some light on the felt making process and he agreed to do this interview. I’m so excited to share his words. I’ve only scratched the surface and already I’m finding that felt making is more about art and intuition than formula; that you could spend a lifetime studying how hammer felt affects piano tone so drastically. Established in 1783, Weickert is over 230 years old! The trade secrets, production notes, and piano technician feedback have been handed down so that this closely guarded secret of felt making lives on. But don’t take my word for it… let’s hear it from Jack.
Weickert and Wurzen are some of the oldest names (THE oldest??) for felt manufacturing in the world and yet the Weickert felt has been “re-introduced” again for hammer manufacturing, correct? Can you tell us a little history about the name and origins as well as your involvement with Weickert and Wurzen?
Wurzen is the oldest existing felt plant of wet processed felts in the World. The oldest. Basically, I was very lucky to come across this beautiful opportunity to re-introduce the old legendary Weickert Felt. All the know-how had disappeared between 1945 and 1991.The Weickert company was expropriated in 1945 by the Communist government and the family fled to the West. The last owner of the company was Alice Weickert, who was an American and had married into the Weickert family. Steinway New York was one of the largest US customers for Weickert hammer felt. I am the fourth generation of textile makers, third as felt makers in the Brand family. All previous generations lost everything due to wars and expropriations, my dad and mom started in the West with nothing after WW2. I am the first in four generations who can build on something.
In 1991 my dad asked me if I was interested in coming back to Germany to look at my grandfather’s plant which couldn’t be salvaged and also at the former Weickert felt plant.
To make a long story short, my dad and I re-privatized the old Weickert plant in 1991. We got a phone call from Renner, Germany asking us whether we could produce the old Weickert felt. We were lucky, the old production recipes were handed to me by an old former production manager of Weickert’s. We ran some materials and the hammers were sent anonymously to Steinway. The response from Steinway (who did not know who had made the felt) was:
– this felt reminds us of the old Weickert Felt
– where is this felt company?
– and we want more
The rest is history. The PTG (Piano Technician’s Guild) of Germany came to the Wurzen plant in 1992, and conducted blind tests on four different grands and the difference in tonal result was significant. After that our supply for Wurzen/Weickert hammer felt was always sold out. Capacity has steadily increased to the point where today annually 180,000 to 200,000 instruments are outfitted with Wurzen felt, about the same amount as in 1903 when ‘Weickert’ felt already had a widely recognized name in the piano world.
Your company Brandfelt.com – how did you get into this business? Did you grow up always wanting to manufacture felt?
I basically learnt felt around the breakfast and dinner table. Our living quarters were at the felt plant. My parents sent me to Canada in 1971 because they wanted me to grow up in a country where there hopefully would not be wars. A small felt plant was founded in Toronto, something to fall back on, in case everything gets lost again thru political turmoil.
Personally I am a production/product development guy who identifies with a natural product like wool felt and who got lucky to stumble upon the challenge of piano felts, which is probably the most difficult felt to make. My colleagues and I didn’t invent the Weickert hammerfelt production method, we only re-introduced it because of fortunate circumstances together with determination and real interest in the product by a whole bunch of people in our factory. At this point I also want to thank all the piano builders and hammerhead makers in the world who showed genuine interest in making a better product and let results speak for themselves.
Piano felt is a small part of our overall world sales, but it is one of the most challenging and interesting ones. We have manufacturing and converting plants in USA, Canada, Europe and Far East.
Let’s get into hammer felt making. How many basic grades of felt are there?
First of all I would say there are today about four major different manufacturing methods in the world for piano hammer felt.
1) I call it the Royal George method out of England, whose technology was purchased by a Japanese felt company in the early 90s,just as the Wurzen /Weickert hammer felt method was being reintroduced into the market place. Royal George as a felt maker does not exist anymore.
2) The VFG method which is a manufacturer out of Germany (in the former West Germany before German reunification in 1989).
3) The Japanese/Chinese method which existed before a Japanese felt company purchased the know how from Royal George, England.
4) The Weickert/Wurzen method which was developed in 1847 near Leipzig and which by 1861 was internationally recognized. By the early 1900 ‘s the J.D. Weickert Piano Forte Felt Company supplied top hammer felt for about 200,000 annually world wide.
Each of these felt methods provide different resiliency or elasticity effects in the felt, hence different results at the hammer head maker and different tones at the voicing stage (because each type of felt will react different in voicing even if hammerhead making method, voicing method and type of instrument are the same)
Each felt manufacturer offers in addition different grades. The Wurzen Felt company offers 4 different grades:
-Piano (which can also be used for grand instruments)
-Weickert Special (the latest and probably also the best in most instances, especially for grand instruments)
All these four different grades by Wurzen are being produced in accordance with the basic principles of the legendary Weickert hammerfelt manufacturing method. The difference in the above felt grades can, for example mean different wool blends and/or slightly changed processes, for example with more or less hand labour in the different stages of production. But we always follow the old Weickert method which nobody else does in the world at the moment. Basically the different grades offer different kinds of elasticities to the hammerhead maker and end user. Weickert in the olden days also carried four different grades of top hammer felt.
What exactly is virgin wool? I presume it doesn’t refer to non-promiscuous sheep…hahaa Do piano hammers primarily use virgin wool?
Virgin wool is wool shorn from live sheep, not dead sheep (usually raised for meat production. Those wools are called skin wools which often are chemically removed). Usually live animals get shorn twice or once a year depending on the food environment and what type of length or fineness of fibre is required. These are virgin wools.
So the big question: What raw materials and process make for great piano felt? What factors affect tone?
Using the right fibres is very important and a prerequisite. The Wurzen/Weickert felt company has a long tradition of knowing what fibres are best suited and how these fibres have to be processed after they are shorn from the sheep. We have our own company specific recipes and specifications, which we consider proprietary. But the different steps in the manufacturing method are essential to provide good tone results in the end (fibre blend, mixing, carding, felting, fulling, finishing). This is where the real know how lies and which differentiates the Wurzen/Weickert felt from all other methods in the world.
In my seminar on the principles of felt making I hand out identical pairs of felt samples which represent the different stages of production, i.e. felted or fulled material but which feel quite different from one another in your hand when you squeeze, bend or just touch them. The pairs of samples are identical in fibre, dimensions and weight and still one will feel harder or stiffer than the other (or one surface feels smoother and the other rougher). Why the difference? Well it is the difference in production method. For example the one sample may have been exposed to high temperature steam whereas the other to low temperature steam affecting the moisture content in the felting and interlocking of fibres process (for fibres to interlock properly the scales on the fibres have to properly open up before they can interlock which only happens if you have the right temperature and moisture content),the right stoke and speed settings of the felting plates, plate patterns, type of transportation cloth on which the material gets felted, etc…
The point is the resiliency/elasticity of the product always changes if one changes any of the parameters in the production process. So that is the craftsmanship which one has to attain thru a lot of trials and errors. Specs of weight and dimension and which fibres alone don’t define the elasticity of hammer felt. One needs to know how these wool fibres are being processed under what parameters at each step of the production process.
The end result is a certain felt elasticity which stands for, in our case, for the Weickert method of hammer felt making. Generations of felt makers at our plant in Wurzen developed it in conjunction with and with feedback from piano builders and hammerhead makers since 1847. The Weickert method is proven and with the help of a good hammer head maker who will adjust his method to our felt, it will produce a beautiful tone. It is very important to work closely with a hammer head maker and also with the piano builder or piano technician to get optimal results. You can have great felt but without the right hammer making method you will end up with mediocre results. Vice versa a good hammerhead maker who knows his stuff and uses a mediocre piece of felt can still get a decent result but not the optimal one.
We know of many examples where the identical Wurzen felt hammer specification was made into hammers by different hammerhead makers for the same piano factory customer, one was good and the other was rejected. The conclusion is that without all three parties working closely together (felt maker, hammer maker, piano builder) you almost have no chance to get the optimal tone result.
To answer your question ‘what affects tone’ I would say it is almost endless but it helps to know what felt and which grade is on your hammer,who made the hammer and what method was used (ie hand vs Hydraulic press, prepress or not, shape of how felt is cut from sheet, what temperatures and times in presses etc…) and what design of instrument and tonal taste one wants to achieve.
The art and science behind felt making, the experimentation, the feedback from builders and technicians – it’s amazing that the Weickert “secret recipe” was not lost. Pianos around the world might have been changed forever had these production notes not have been found and handed to you.
Yes! The basic trade secrets were handed over to me by the then production manager in 1991 who in turn got it from the previous production manager who was still working during the Weickert family era. The last production adjustment to the Grand D hammerfelt spec production sheet for Steinway was initialled and dated in 1933.
Wow! That’s incredible. For those wanting to see felt making in action, here’s a video link to the Brand Felt Company in Canada. I’ve learned so much about an area of pianos I knew so little. And scratching the surface one quickly realizes how broad this speciality is. I just want to convey my thanks to Jack for taking the time to do this interview. Your insights and expertise are not only helpful but inspiring and captivating.
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