Really cool. It would be really useful though if I could sort the results, for example, by album/track number. Seems like a REALLY useful service nonetheless. Congrats.
EDIT: Also, sometimes people combine multiple songs into one youtube video, for example http://youtu.be/J0FawK4G_AY They seem to show up in your player as only the first song. This is a lot more complicated then my first suggestion, but some sort of detection of that (and maybe the possibly more common case of full album videos) would help save some confusion when users play one song and get another one for free. (BONUS!)
EDIT2: Also, allowing only one video for any given song has issues, for example, when the first result is a live video or otherwise bad quality. Maybe just a right click menu that lets you select "See alternate videos"?
EDIT: Also, sometimes people combine multiple songs into one youtube video, for example http://youtu.be/J0FawK4G_AY They seem to show up in your player as only the first song. This is a lot more complicated then my first suggestion, but some sort of detection of that (and maybe the possibly more common case of full album videos) would help save some confusion when users play one song and get another one for free. (BONUS!)
EDIT2: Also, allowing only one video for any given song has issues, for example, when the first result is a live video or otherwise bad quality. Maybe just a right click menu that lets you select "See alternate videos"?