Modern piano tone has also changed from late 19th century through the 20th century due to the further development of the piano’s power and due to musical tastes and styles.
Pianos developed to their current incarnation by 1920. Most of the significant changes had already been incorporated by then. The piano’s tone is created by both the soundboard vibrating and mostly colored by the piano hammer and its character.
The modern piano hammer is made by gluing 100% high grade wool felt to a wooden shaped molding under high pressure in a hydraulic machine forcing the felt around the wooden core molding. This creates both compression of the felt and surface tension. The machine has also the ability to heat the felt and the degree of heat can compact the felt more and create a ‘brighter’ hammer.
Historically, hammer felt was also ‘wired’ or tied at the bottoms of the shoulders to remain secure in case of glue failure. Today, many hammers are ‘T-stapled’ which looks like this I—–I through the felt and molding and out the other side. Wiring provides much more control of felt compression and tension than T-staples and is more expensive.
The highly prized pre-WWII piano hammers were made with long-grain wool from specific breed of Egyptian sheep that had certain magnificent qualities for piano tone. The felt was very supple and strong which created the ability to take considerable compression and yet not become hard as shorter grain, current felt.
These wonderful hammers yielded a tone that had many levels of dynamic and changed tonal quality as you played louder. The tone would ‘blossom’ or change with the pianist’s touch and yet would be plenty brilliant and bright when required in concerto and solo playing.
Today, due to the lack of good quality, long grain felt, we do have good German felt and English felt but mostly felt is shorter grain now. Since WWII, it has become a common practice to ‘brighten’ piano hammer felt with the use of a clear lacquer solution to harden the felt through introduction of lacquer solids inside the felt. This yields more body and drive to the tone but can become ‘metallic sounding’ because playing will drive the solids closer to the tip of the hammer – making it hard.
Traditional German piano tone and pre-WWII American piano tone had the qualities described above with blossom of tone, and a soft, yet supple tone becoming bright when pushed. Today’s piano tone is has fewer dynamic color levels with a soft, mezzo-forte , forte and fortissimo sound but not as before. This is due to either hot-pressed or lacquered hammers that are, inherently, less resilient and harder.
In the 1980’s, I asked the famous New York Times music critic, Harold Schonberg, during a lecture, how he believed concert pianist’s tone and tonal conception has changed during the 20th century. Schonberg, noted for his book on famous concert pianists, THE GREAT PIANISTS, responded that Rachmaninoff could make beautiful tone on any piano and that his sound would sound the same today as before. I commented that with the changes in hammer manufacture, even the great Rachmaninoff could not make tone that was ‘not there to be had’. Mr. Schonberg could not comment on changes of piano tone affecting pianist’s approach to the piano because he always associated pianist’s tone with their touch and not the instrument, per se. But I can assure you that there is overall less detail in tonal expression in the majority of today’s players when compared to Rachmaninoff, Rubinstein, Hofmann, Cherkassky, Michaelangeli, Wild, Horowitz, Moiseiwitsch, etc.
My great friend, the late Earl Wild (who died just four months ago at 94, was considered the last great Romantic pianist. Earl could make gradations of tone and color on any piano but was still limited to what the piano would give him. Prior to an all-Liszt recital in Utica, NY, the piano had a strange sound when the soft pedal (una-corda) was used and I worked late into the night to try to lessen it. During the recital, Earl, as great pianists can do, actually memorized, instinctually, all the tonal anomalies in the piano and adjusted to cover the effect. The net result was that even I, the piano technician who knew the piano intimately, did not recognize it was even the same piano. He had fixed the problems with his fingers!!!!!!!!!
Pianists are amazing beings.
………..to be continued.
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