Cool design, good UI, stats look good. The album art is big and cluttered for my taste, I'd prefer a list view.
Don't want to get too negative, but I don't think this can seriously compete with spotify's built-in song discovery. They have tons of advantages in that respect, some moats (can only play 30s with API, integrated playlists), and some by virtue of scale (can compare with other people's listens to find new tracks).
The only way I can see this working is with features that spotify doesn't provide, like social recommendations or shared listening. Still a good showcase of your programming + design skills though!
I made a jukebox prototype for spotify a while back (http://spotifight.herokuapp.com/, click spotify authorization at the bottom), and got around the 30s limit by playing the songs over users' spotify instead.