🚀 go-pugleaf

In article <4671@orca.WV.TEK.COM>, mhorne@ka7axd.wv.tek.com (Michael T. Horne) writes:
> In a recent article by d88-jwa@nada.kth.se (Jon W{tte):
> >>frequency scaling algorithm, perhaps by doing a digital mix with a reference
> >>(digital) carrier (i.e. ref = 100 Hz for a 100 Hz shift upward in frequency),
> >>followed by a carrier and lower sideband suppression...
> >
> >As I've said before: that's not scaling, that's OFFSET ! You can't do that
> >to MUSIC, because music has a realative overtone spectra.
> 
> context), I believe that the question is about scaling an arbitrary `musical'
> (from the viewpoint of the average person) sequence up or down in frequency
> while retaining the `musical-ness' of it. :)  I still stand by my suggestion
...
> >And imagine the effect this has on complex waveforms like a violin or a
...
> Could you please elaborate on the typical spectra of a given note on a
> piano or violin?

Actually, it doesn't matter what instrument (including the human voice) you
pick.  They all contain harmonics and overtones which (to sound right) must
be multiples of the primary frequency.  In addition, instruments like the
piano have chords.  These notes have (generally) frequency relationships
that must be preserved.  An offset will *not* do this.  (It might be
interesting to hear the result).  Basically the shift must vary with
frequency to be accurate.  This still might be doable in frequency space.
A simple shift of the frequency function would produce an offset, therefore
shifting the higher frequencies more than the lower might do the trick.


-- 
  Terry Ingoldsby                       ctycal!ingoldsb@calgary.UUCP
  Land Information Systems                           or
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