So maybe it's not an art. Many radio people would argue that non-commercial stations practice this all the time. I personally would argue that they actually are "block-formatted" most programs in fact have a format. it's somewhat unfortunate that the reggae format the death metal format and the polka format may be in close time proximity.
What I am talking about are the commercial stations that dont really have a format. Some of you are thinking "Jack" right now but that too is a format. For all the hype it's really just deep catalog AC/80s but I digress. I mean actual commercially licensed stations that actually sell ads, that just don't fit conventional format definitions. In previous years the addition of oldies to a standards playlist might have qualified (or vice versa) , like WGUL-AM in Tampa. They ran deep catalog oldies beside overplayed vegas crooners. It had a loyal niche audience, but in that market WRBQ killed them in ratings. I had an inkling that they wouldn't last, and sure enough last month they dropped it for talk. A nice straight standards station might have been able to eek by with the demo in that market.
Anyway I'm on a tangent again. My examples today is New Rochelle 93.5 WRTN. (some of their programming is run on their AM sister station WVOX 1460)
I first heard WRTN over two years ago. They ran a very straight-ahead standards station; lots of Sinatra, a little big band, a lot of Glen Miller As they say "It is what it is." And then they added some reggae programing. It stoof out as kind of random but they blocked it out pretty well with talk programs on each side of the slots.
I am guessing these shows were popular because they added more., lots more. Today the station runs reggaeton, reggae, tropical, dancehall... all sorts of Caribbean music and then few straggling hours of standards. But this new format is a little awkward.
If they played more rap you could call it Hurban. If they homogenized it more they could call it tropical or even Reggae. But they don't. The playlist is all over the place in terms of genre. but in terms of demo it's not. They don't appear on the recent Bridgeport or Stamford Arbs but I dont think they participate to be honest. They've found a community that clearly wants them to be there. And the community has found a station that wants to be there for them. I cant argue with that.
The president of Whitney Radio the parent Co. to both stations, William O'Shaughnessy is a bit of a willful crank who reminds me of other brilliant wilful cranks that ran massive media groups on to great success. men like like Ahmet Ertgun, Ted Turner and the like. His impressive bio is here: http://www.wvox.com/wo/index.htm including where to buy his book.
Nothing explains why he runs WRTN station the way he does. I hope that they keep it up. But like so many eccentric gems out there, I can only beleive that ineviably the big money offer will come and it will be sadly swallowed up by some large multi-national conglomerate.