if you can swap on the fly between the song and not having the song, I can see a LOT of tactical viability and I'm actually a little giddy at the possibilities.
If it amplifies damage, this means you activate it to set your DoTs, then swap out of it when mechanics come your way, then back in during "safe spots"
It also looks like it might give Skill Speed viability if they make the changes they said they were going to (which was a nebulous "We r teh changin it")