This is what we need for other media - a canonical, universal way to refer to a particular piece of music or other recording, that we can excerpt and link to as part of our own creation. Sending compressed copies of tunes synchronously once to a few listeners is imposing the limitations of radio onto a new medium that has the potential to be far more flexible and expressive - it is like early cinema, where a single fixed camera would film a whole play, with the proscenium arch neatly framed in the shot.
While we don't have excerpting down, the reliable identifiers used by Bitzi can refer to exact instances of media, and the MAGNET-URI proposal provides a way to handoff further processing from a website to one or more helper apps, such as cataloguing, sharing, or content-delivery utilities.
Further, the "Judio: P2P-Leveraged Net Radio" concept a few entries down is a more radical formulation of something Mr. Marks was also musing about recently. He suggested using actual local CD-tracks to feed virtual net radio channels, where I suggest P2P networks.