Ok so hear me out here. Psychology journals were trying hard to make people release their data for submitted papers. Some had the idea of marking papers with released data with (meaningless) badges on top. This alone made like 50% more people release their data. Sooo I think it could REALLY incentivize posting if you put some sort of marker, badge, or verified check mark for a) first expression of a song, b) most-liked expression, and c) "artist's pick" where an artist can choose their favorite expression of a song. I think these would improve engagement to a large extent. And the last one would definitely get more artists involved