HD does stand for High Definition, which in this instance is digitization of the broadcast signal.

Emaidel, I don't quite agree with your point. I think you may be a bit too focused on the quality of the sound as opposed to the music itself. Granted analogue radio may be somewhat compromised in general, but I've heard it sound very engaging, which is more than I can say for some CDs I own. We have many excellent stations here in Los Angeles, including some of the finest classical stations such as KMozart and KUSC (Uni So Cal) and there are more. How about KJazz out of the Uni of Long Beach. I guarantee you they do not use a cheap CD player or TT, and furthermore, their broadcast equipment is likely better than most of our own gear. Did you know that Ed Meitner of EMM Labs supplies equipment to the better stations?

I can easily become captivated by a wonderful piece of music on analogue radio, and don't find myself analizing the sound quality, because its good enough to get involved in the music.

I would hate to see analogue radio disappear completely.
Btw, I don't believe The live broadcasts on KCRW are compressed, but broadcast directly from the studio as the artists play. The sound is first rate I assure you.