[comp.music] freq shifting vs pitch shifting

james@astro.uucp (James McCartney) (07/26/90)

   The 'big' point you may be missing is that the input wave may have
sine components at several frequencies. If we are just dealing with
sine waves there is no difference really, you would just use a different
'factor'. If the input wave has components at 100, 200 and 300 hz,
and we pitch shift with a factor of 1.1 then the output wave will
have components at 110, 220, and 330 hz -- still in a 1:2:3 relationship.
however if we freq. shift by 10 hz the out put wave will have components
110, 210, and 310 hz the waves are now in a 11:21:31 relationship which
is fairly inharmonic. So in other words pitch shifting maintains the
harmonic relations of the components whereas freq. shifting changes
the relationships.
	--- james mccartney