GnuMusiq/listening stream

Where a topic subscription relates to saleable releases (albums/CDs, usually), a listening stream relates to individual songs -- basically applying the same choice techniques (reviewers, weighted aggregation, etc.) but with the primary goal of creating a highly-personalized "radio station" for each listener.

Listeners would have the option to rate each song they heard and purchase (or pre-order, if not yet released) the album(s) on which the song may be found. (They could also buy the individual song.)

Listener ratings would add to the overall rating for each song; high ratings would cause the song to pop up in more places until its appropriate audience had been statistically determined.

Listeners would also have the option of downloading their "radio station" so they could listen to it in other venues (e.g. on a portable device or while driving). The user would enter the storage capacity of their device, and the site would attempt to fill it with an appropriately-tailored playlist. All tracks downloaded would be listed in the user's account so that they could easily go back and make purchases or ratings.

(This is apparently similar, but not identical, to what Last.fm does.)