How can I alter the tempo of a song?
Audacity has a change tempo effect you could try in the Effects menu. It might end up making it sound funny, so you will obviously want to listen to it once the effect is applied, but it doesn't simply play it back faster which would change the pitch (that is the change speed effect.)
If my math is right you will want to change it by +11.4% to get from 3:54 to 3:30.
You can also use the atempo filter with ffmpeg:
ffmpeg -i input.mp3 -filter:a atempo=1.114 output.wav