However, before heralding sports as radio's programming panacea, let's look at activity at the station level. Last year, an FM rock station in Philadelphia changed its format to sports talk by simulcasting an AM station in the same city. "They basically blew up a rock station with revenue of $11 million," an industry veteran says of the CBS Radio-owned operation.

In San Francisco, a country station got a similar makeover. Although its revenue was only $6 million, the change to sports radio mandated by owner Entercom Communications Corp. left the City by the Bay the largest market after New York without a full-power country station. It also increased the number of sports radio outlets in San Francisco to three.

But is the format flight really to sports talk? Or is it from the music jock and all the genres that he and his brethren, if you'll excuse the archaism, spin? Technology suggests the latter.

People may be listening to music more than ever, but they're listening to it from more sources than ever, including iHeartRadio, iPods, Pandora, Sirius XM, Spotify and so many other digital delivery systems that loyalty to a station, or even the medium, is no longer a given. This is especially true of youngsters, whose listening alternatives to radio liberate them not just from drive time but all the time.

For advertisers, music radio's diminishing power to engage is cause for alarm. Why spend on this peripatetic audience when at the slightest provocation (a commercial interruption, say, or a song not in keeping with a listener's rarefied tastes), it's either off the medium or off to another song? As the industry veteran puts it, "Advertisers need a format where the audience listens through the entire commercial, and the only way to do that is to keep it interested in what it's about to hear on the other side."

Hence the heightened appreciation for sports talk and its evil twin, talk radio -- a format so flexible it warrants as many subgenres as radio has genres. "They're radio's equivalent of reality TV," the veteran explains. "Music you can get anywhere, but talk as content is still unique."

The uniqueness of sports-radio talk would be well and good were the population producing new sports fans at the same rate the industry's legacy music audience is finding ways to escape the quid pro quo inherent in commercial radio. But it's not. Rather, like the rest of society, sports fans are being splintered into demographic pieces. It's just that those fanatic about a mainstream sport remain more committed to listening to a radio program about it than fans of a mainstream band remain committed to waiting for one of its songs to come into rotation.

This doesn't bode well for the medium once sports radio plays itself out as a programming panacea and bumps against diminishing returns. But it does bode well for creativity of the sort displayed by industry gargantuan Clear Channel Communications Inc. when it launched iHeartRadio as a Pandora alternative.

Last May, after a mere eight months in the field, Clear Channel announced that its customized Internet-streaming radio platform had already enlisted 10 million registered users -- "faster than all other popular entertainment and communication platforms," it said, "including Facebook, Twitter, Pandora, Spotify and Instagram." And though that's a smaller audience than the one amassed by Pandora, which began its 12th year in January with 125 million registered users, it's still a fast enough start for debt-burdened Clear Channel to steal another page from the Pandora playbook.

Just as Pandora Media Inc. undertook an initial public offering in May 2010, Clear Channel should send iHeartRadio into the public markets. Granted, with a market cap of $1.7 billion, Pandora isn't riding nearly as high as it was when its IPO price valued the company at $2.6 billion. But it's so far ahead of the $174 million market cap accorded Clear Channel parent CC Media Holdings Inc. that it's safe to say iHeartRadio isn't being valued at all.

An IPO would change that, but Clear Channel better hurry, for the next sound it's likely to hear is Apple Inc. big-footing in music again.