Ed Cooke - the memory champion Joshua Foer writes and talks about (in part) - has co-founded a site with cognitive scientist Greg Detre for memorising vocabulary (or indeed any "word set" users create). The principle is the same as that which forms the basis of Foer's talk - transforming the information you want to remember into something vivid or extreme in any sensorial aspect, and then revisiting that memory to firm it up. It certainly works for me: http://www.memrise.com
And maybe keyboard support for 'notes' - every letter on the keyboard assigned to ABCDEFG and the black notes in between. Then you could, say, plug in a written text and see what happens.
I wonder whether, if there were all 12 tones on the Western 12-tone scale, it be more cacophonous. Somehow, with two octaves of only white notes, as it were, and the tendency of users to move about constantly (because it looks pretty and you get the exciting perceptual feedback of changing the sounds), most of it doesn't sound bad. Great idea.
And I think that that assumption/argument is invalid. I'm sure I've read somewhere about studies of user behaviour in, say, iTunes (your personal music) compared to on a subscription service like Spotify. The studies showed that people who had access to a limited amount of music of owned music would listen intensively (fewer songs, lots of times); whereas people with access to a subs service would listen extensively (more songs, fewer times). There was some stat about a favourite song being listened to far less frequently when there was more to explore.