Yatm (Yet Another Time Machine) is a very simple command line audio player. Its main purpose is to play audio files at a different tempo while retaining the original sounds pitch. This is very useful for listening to audiobooks at a slightly higher speed than they were originally recorded with. It can also be helpful when listening to musical passages at a slower speed to be able to distinguish the different notes more easily.
Changing the pitch while keeping the tempo is also supported. Musical cents and semitones can be used to specify pitch change. This makes it easy to use for musicians. The notes you have are in G but the recording you'd like to play along with is in F? No problem, transpose the recording up two semitones. You'd like to play along with this baroque recording that uses original pitch? Just tune the music up about 80 cents and you should be fine.