I have a few questions:
1. Does the song have to be from a ranked beatmap, any beatmap (including the graveyard maps or unranked maps), or any song at all?
2. As for duets, will vocal (multiple track) mixing be allowed? Especially if both of us will be recording each part separately?
3. Can we sing an acapella of an instrumental? Example would be <a href="http://www.youtube.com/watch?v=ALhAXtFR1LM&feature=youtube_gdata_player">this</a>. (for lack of a better example) But only two voices will be heard. No mixing and the like (not planning on singing acapella but I want to know your thoughts on this)