By Nickelback, or...?
(really sorry, music is a vast area, but that's the only one I know of).
To get to the point of that, you're the Rival in Sienna, yeah? (as in, his name is Harry). The Rival's theme could be your favourite song or something, that's the idea I had. Well, a rendition of your favourite song. A Pokemon-ish rendition.
:P