On Thu, 23 Jun 2016 14:31:42 -0600 S D <stephen.doonan@xxxxxxxxx> wrote: > On Jun 23, 2016 6:41 AM, "fred" <f.rech@xxxxxxxx> wrote: > > Thanks for this acoustic & physics piano lesson :) > > I'm pretty sure than am not alone on the list to have a very little > understanding of how & why a real grand piano is built. > > Cool to reconnect to physical instruments in this sampled world! > > Greets, > > -- > > Fred, > > --- > > :-) An acoustic piano is far from an ideal sound generator. In fact, it is > a complex collection of imperfections striving for an unattainable ideal. > > If we wanted a pure sound, we would use a source that produced only pure > waveforms like a sine-wave generator, and perhaps added the various pure, > in-tune harmonic frequencies at various (and diminished) volumes to the > fundamental tone. > > A piano has 88 keys and string collections (most notes have 3 strings per > note, bass strings only one wire string with a copper-wire coil wrapped > around it, per note). The strings for any particular note (tone frequency) > are often slightly detuned, so that only the middle string is more or less > perfectly in tune, while the two strings to either side are detuned > slightly in order to make the note's sound richer and fuller, with beat > frequencies and other out-of-tune artifacts introduced. > > In addition, most pianos are "stretch tuned," which means that the bass > notes are intentionally and progressively tuned flatter and flatter by a > small incremental amount, while the treble (high) notes are tuned > incrementally sharper and sharper. This is because the bass notes have such > a low tone that it is their harmonic frequencies that are heard more > clearly by the human ear, and those harmonic frequencies are often sharp (a > higher frequency than they should be if perfectly in tune). So the bass > notes are tuned so that the harmonic frequencies are heard more in tune > while the fundamental frequency is slightly flat (lower frequency than it > should be if it were perfectly in tune). > > Meanwhile, the treble strings, because they are stretched so tightly in > order to produce such a high pitch (frequency, tone), immediately decay > flat (become lower in frequency and out of tune immediately after they are > struck by the piano hammer activated by the key pressed by the performer. > So the treble notes are tuned a little sharp, so that the decay (the sound > as it becomes softer immediately after it is produced) sounds more in tune. > > Add to those out-of-tune compromises the fact that the scale we now nearly > universally use, the equal-tempered 12-tone scale that allows for playing > in any key, is a compromise between the pure tunings of any specific key, > so that nearly every note in the scale of any key is at least a little out > of tune. The intervals of perfect fifths and perfect fourths, derived from > strict mathematical relationships, are all altered, so that the fourths are > stretched (tuned sharper than they should be) and the fifths are flattened > (tuned closer to each of the two tones than they should be), which means > that nearly all music that we hear, and nearly all instruments that play > together in an ensembles, are ALL out of tune to one degree or another. > > In addition to all of that, people usually intentionally introduce other > imperfections into their sounds or music, such as the distortion frequently > used with electric guitar. > > Music is a vast collection of imperfections. Regarding modeled pianos, if > the model is too pure and perfect, people complain that it doesn't sound > realistic or authentic. If it models the actual acoustic instrument's > imperfections too well, they complain that it sounds too "muddy," > distorted, not clear or pure enough, etc. > > All of this means that it is literally impossible to please a > perfectionist, because there is almost nothing perfect about music or the > production of sound, and also because a perfectionist, if he tries very > hard, can always find something, even the smallest thing, that he considers > imperfect or not ideal. :-) Life must be very hard for the perfectionist! > > However, all that said, our very precisely out-of-tune 12-tone equal > temperament scale, in use for pianos and most orchestral or band > instruments, actually allows for an incredible amount of extremely complex > and beautiful frequency and harmonic relationships that are impossible when > using a completely mathematically pure single-key scale. Without this > "imperfect" tuning, modern music since the time of Bach, including the > beautiful Classical, Romantic, Impressionist and modern music of Mozart, > Beethoven, Chopin, Tchaikovsky, Rachmaninov, Debussy, Ravel and hundreds of > other composers would not be possible. > > OK-- I apologize for such a long-winded response! :-) > > Best wishes, > Steve Fascinating info. I know just a small amount of the detune info, but not *exactly* what was done, and had no idea of why - although like many things once it's explained it seem perfectly obvious! :) Thanks very much. -- Will J Godfrey http://www.musically.me.uk Say you have a poem and I have a tune. Exchange them and we can both have a poem, a tune, and a song. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
