Noun to describe something which evokes emotion

Is there a noun that can be used to described an object or idea's ability to evoke emotion?

You've asked for a word that covers ability to evoke emotion, but then in your example you include the word emotion, so it sounds like you just need a word for the ability to evoke? In this case source would work pretty well:

As a universal source of emotion, music is a potent cure for loneliness.

But if you wanted a word that covered the whole bit:

As a universal xxxxxxx, music is a potent cure for loneliness.

I can't think of a word that does all of that :-/ but if there is, I'd love to know it.