Word for good music that channels a lot of bad energy into good energy
Cathartic is the word you are looking for, but soothing/calming comes to mind.
Catharsis is usually only associated with intense emotions.
For me, the word that sums up what you're describing is "therapeutic," Which means:
Producing good effects on the body or mind; treatment or cure
Especially in the context you gave: "this song is very therapeutic to me"
Which would mean that the song rejuvenates and heals you, either physically or emotionally.
Merriam-Webster