I remember 1972.

In 1972, I got my first FM radio. At that time there were FM stations that actually played stuff -- in retrospect it has been called "progressive rock" -- that was not Top40. You could hear "B" sides, album cuts, and stuff on tiny labels. Stuff that is only played on college stations nowadays -- as alluded to above.

Is this because there were more locally owned and controlled radio stations back then, and the deregulation of the radio waves has led to LCD (i.e. market-driven) programming? Is it a change in advertising targeting, such that non-mainstream radio stations can't quantify/qualify their listeners enough to attract adverstisers? Were people who owned small radio stations content with a tiny market share, and their advertisers with the same?

I wonder what is different between now and 1972?

Alex