change key of mp3 song with java

Question

I know there are a few posts about various media frameworks out there, but I am looking for something a little more specific.

I would love to be able to take an mp3 and transpose it to a new key.

Any suggestions?

Answer 1

The easiest way to do it is to play the mp3 faster.

If you play the mp3 twice as fast (so in effect skipping half the samples) then the pitch goes up one full octave. The downside of this approach is that the music also plays twice as fast.

If you want to change the pitch, but leave the speed intact, you'll have to do fancy sound processing. The algorithm you're looking for is called pitchshift.

In any case, you need access to the raw samples before they are played to the sounddevice.