In the languid wake of slowed-down Dolly Parton,
Jason Kottke Tim Carmody offers a splendid guide on how to make your own slow jams, with a few of his own to listen to. The trick, he writes, is to remember that music is keyed to specific frequencies--notes!--and failing to scale in accordance with them may produce uncanny results.
Here's the formula for slowing or speeding up a recording to shift the pitch but generally stay in tune:
(2 ^ (semitones change/12) - 1) *100 = Percent Change
So -- as one does when procrastinating from remunerative work -- I made an Excel spreadsheet.If you want to drop two semitones, you shift the speed down by 12.2462 percent; drop three, you shift by 18.9207 percent, which significantly changes the track.
For your enjoyment, I have already produced Slow Yakety Sax.