Re: OT: Apple has a patent on tremolo!
Re: OT: Apple has a patent on tremolo!
- Subject: Re: OT: Apple has a patent on tremolo!
- From: Richard Dobson <email@hidden>
- Date: Fri, 02 Mar 2007 20:52:48 +0000
Jeff Evans wrote:
? Seems to me that what Kurzweil is talking about is merely that they
offer a chance to specify the Hertz of a pitch instead of using a named
pitch predefined by equal temperament. This would allow one to affect
the beat rate produced by harmonic combinations, tuning for example a
major third so that it was beatless, as in "just" intonation.
It could also be used, true, to create an artificial tremolo by
slightly detuning two waves of the same nominal pitch, but the process
is not automatic as it is in the patent. The patent covers an automatic
method, simple as it is, of making an artificial tremolo constant over
a wide pitch range.
But that doesn't mean I believe the the patent office actually looks at
these applications.
What's to automate? Detuning by interval is a common procedure (as used
for example in harmonizer efffects) - the interval might be as much as
an octave, a major third, or some fraction of a semitone. The second way
is a fixed frequency offset, as in the Kurzweil example - just as
common. It is simply a matter of providing the parameter to the user.
Both will likely be provided together, so you get conventional keyboard
tracking ~plus~ the constant-Hz shift - as clearly described in the
Kurzweil manual, and in the patent description and "circuit" diagrams.
There is even a third way to frequency-shift detune, which is to apply
the fixed offset harmonic by harmonic, which ostensibly can only be done
when the synthesis is by additive oscillator bank. This makes literally
all beats the same - but of course the timbre detuned in this way
becomes increasingly inharmonic (883/443 != 2) as the difference
increases. It is a standard additive method to achieve structured
inharmonic timbres. The sort of thing that might be left as a student
exercise in classes teaching Csound, Max/MSP, etc. We even have pvoc (+
peak detection) processes dating back decades, that apply this linear
frequency shift to a sampled sound.
All three methods are therefore long-established and standard practice.
Any patent can only be valid if it finds some cheaper, faster or
otherwise novel way to do it. To do this it first has to establish a
~genuine~ problem, where solutions either do not exist, or are
expensive or intractable for one reason or another. There is no evidence
of any such advantage even claimed in the patent (and, um, patently, the
"problem" hardly exists as such), which simply thinks it has discoved
the idea of frequency shift. Unless of course they are trying to patent
addition?
Richard Dobson
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