I built a little MAX Patch that does this, the equation is:
A= tempo 1 (152) or lesser bpm
B= tempo 2 (175) or greater bpm
(1-(a/b))/(1/12)
The first part of the expression will give you the percentage that the first
bpm is off by the second then you divide that by (1/12) or (one semitone,
[12 semitones per octave]), that will give you the amount of semitones to
shift the track by. Email me if you want the MAX patch.
-edIT-
quoted 10 lines is there a typical mathematical formula for calculating semitone or 'cent'
> is there a typical mathematical formula for calculating semitone or 'cent'
> difference using bpm?
>
> i.e.
>
> track 1 is at 152 .. track 2 is at 175
>
> what mathematrical equation can i use to find how many semitones (+ - 24) or
> cents (+ - 100) i should adjust track 2 to match the tempo of track 1?
>