I'm a guitarist who wants to learn songs by slowing down the tempo and changing the pitch if I need a different tuning.
Is there a plugin or tool I can use to change the tempo and pitch of songs on Spotify?
I'm using Mac OS X 10.7 (Lion)
Changing the speed of an track in Spotify is (currently) not implementable, as mentioned by Spotify community moderator David -> http://community.spotify.com/t5/Spotify-Ideas/Speed-up-songs/idi-p/171644
Spotify does have an API, but I don't see any plugins that can do this straight from the application.
Pitch and tempo adjust are more common in digital audio workstations like GarageBand and Ableton Live, etc., if you're able to track down software.