Limited spectrum... yet we have so many stations, all playing THE SAME THING,
The reason they are all playing the same thing, is that is what the vast majority of advertising desirable listeners prefer to hear, and the representative sample of the public votes with their PPM devices.
Possibly some others can clarify this, but I think there was a time when the FCC was involved in what format a station could offer. But those were also the days of huge ratings for dominant stations, while others were forced to stick with smaller interest groups. Seems WRVR was "stuck" with jazz for a while because that was its "approved" format.
Once the FCC deregulated and decided that radios were just entertainment and information appliances, in the same way that microwave ovens are food heating appliances, variety on the dial was doomed. Then there was the feeding frenzy that made licenses too expensive for all but huge well-funded corporations. And finally cluster strategies that effectively limit format competition, and you wind up with the top three stations in the NY market playing some of the same music, sharing the same core of listeners, and all owned by one company, Clear Channel, which also happens to own the most radio stations in the country.
And, never forget that almost 40% of the NY market is now Black and Hispanic, and those groups are attractive to advertisers too.
Onetime, Beautiful Music stations WPAT, and WRFM, now serve those market segments, and the kind of people who used to have a choice of four beautiful music stations, two commercial classical stations, a commercial jazz station, and a country station or two, now have none of those formats to listen to.
Some would say that is the free market at work, the scare resources of available frequencies have just gone to where they produce the greatest economic benefits for the most people. Majority rules, and people who like country music, jazz, classical and beautiful music are now just tiny minorities too small in number and economically unimportant to deserve a rare frequency to offer what they want to hear.
Hopefully, Internet radios will shortly become standard in cars, and easier to use in houses and as portables, and will come with an almost unlimited choice of programming. Then an entirely different set of market forces will come into play, and what economists call "pure competition" will exist in what has been a somewhat limited competition for the attention of listeners because of limited spectrum.