Record albums foster content- and object-based community, through the distribution and sale of plastic objects with sound encoded into them. When you listen to the radio, there are likely (at least) dozens of other people who are listening to the exact same thing, at the same time. Radio fosters content- and time-based community (i.e. when you and your friend listened to the same radio show at the same time of the day).
Radios are ubiquitous: far cheaper than a CD player or an iPod, included in all cars, and many alarm clocks. This implies wide and easy access in our society; this is another essential aspect to radio's community-fostering character.
Commercial radio expresses the desires and interests of advertisers and the rather unadventurous producers who are responsible for assembling the songs we hear. Advertising dollars run commercial radio; the songs are filler in between the content: advertisements.
Freeform radio expresses the desires and interests of the individual DJ, herself a member of the community. The DJ's interests are filtered (though very slightly) through the interests of institutions like the FCC, and in my case, the University of Michigan.
Freeform Radio is a performance art for an unseen, uncountable audience.
The DJ plays songs like a jazz musician improvises phrases, or like a classical pianist plays a Bach Invention: with deliberation, curiosity, humor, honesty, and taste (however tasteless). Songs are selected by direct choice, through association with another recording, or completely at random. Continuity between songs is interesting, but may not be consciously pursued. Continuity emergent from deliberate contrast is a powerful experience. Serendipity is the lifeblood of freeform.
It is an honor to be allowed access to this medium. Thanks to WCBN-FM, the University of Michigan, and the FCC.