For a long time, “Kiss” (KISQ 98.1 FM) was a mix of R&B, oldies and newer stuff. Now it’s “The Bay’s Old School,” where Motown rules. KFOG (104.5) long has been the eclectic company, mixing classic and contemporary rock (and folk, blues, reggae and more). Now the music is said to be leaning toward more familiar classic rockers. For years, Alice (KLLC 97.3) featured an alt-rock blend aimed at women. Now it’s gaga for the latest hits.

For loyal listeners of these and other stations, it’s puzzling, how they shift and shake up their playlists. KOIT is “lite rock,” but features Daughtry and Aerosmith as well as Kelly Clarkson and Colbie Caillat. KBWF (the Wolf), a country outlet, plays Uncle Kracker, while pop stations air the countryish Lady Antebellum. KBLX is “The Quiet Storm,” but punches things up with Aretha Franklin‘s “Respect” or Hall & Oates‘ “I Can’t Go for That,” along with Mary J. Blige and Marvin Gaye.

So what’s going on? According to several programmers I spoke with, it’s just radio business as usual.

“There are two primary driving forces: ratings and market research,” says Don Parker, operations manager for Clear Channel, whose local stations include KIOI (“Star 101.3”), “Kiss,” KKSF (“The Band”), KMEL and KYLD (“Wild”). “Our mission is to always deliver what the audience wants.”

He is echoed by Michael Martin, VP of programming at CBS radio (KLLC, or “Alice,” KITS “Live 105,” and KMVQ, “Movin”). “It’s the listeners,” he told me. “People who program radio put up preconceived walls of what listeners want. The audience doesn’t put the walls up. They just like the songs they like.”

A station’s playlist, he says, is “just a reflection of what the audience tells you they want at any given time, and all you can hope to do if you’re in tune is to ride the wave with them. Whether you like Taylor Swift or not, if you don’t reflect her when the audience says to reflect her, you’re dead.”

And, with music lovers’ tastes constantly shifting as they’re exposed to, say, “American Idol,” “Glee” or Lady Gaga, stations try to ride that wave by doing research.

Bill Conway, PD at KOIT, the Bay Area’s leading music station, constantly tests music, even though KOIT plays only seven currents – new hits – at any given time.

Research, he says, “lets us know the types of music our target audience wants to hear.” KOIT is nothing if not careful. “We do tests, catch trends, test songs that we’re not ready to play yet, and wait till they fall into our world.” He names examples like Gwen Stefani, Daughtry and Tom Petty. Because KOIT offers what Conway calls musical “comfort food,” he and music director Julie Shannon are picky about new songs. “I pick currents the way Bob Uecker said he caught the knuckle ball,” says Conway: ” ‘I let it roll till it stops, and pick it up.’ ”

Another proponent of the tried and true is “Kiss,” which recently celebrated the return of morning star Renel. Once promoted as “Old School and Today’s R&B,” KISQ left school for more contemporary sounds for a while, until, Parker says, research informed the station that “the real passion was for old school. We decided, ‘Let’s go back.’ ”

And, just as KKSF has learned with classic rock, playing older music doesn’t mean drawing only older listeners. PPM – Arbitron’s new Portable People Meter technology of capturing radio listening habits – “has shown that it’s not true,” says Parker. At CBS, Martin is talking about how “Live 105” is playing more “gold-based” (older) music. ” ‘Classic hits’ doesn’t necessarily mean ‘older,’ ” he says. “Part of the whole vinyl records resurgence started with college kids. They’re discovering a lot of this music.”

Beyond ratings and research, there’s the never-ending element of competition. Struggling stations emulate successful ones; top-rated stations make defensive moves to fend off encroachers. That’s why, when a Lady explodes – whether it’s Gaga or Antebellum – she is heard across numerous radio formats.

The biggest battles right now include Star 101.3 vs. Alice. KIOI, according to Parker, has been in the Top 3 among 25- to 54 year-old women for over a year. That’s Alice’s target demo, so the CBS station has gone Top 40, duplicating much of the “Star” playlist. At CBS, Martin says the Don Bleu/Ryan Seacrest station is “our No. 1 sharing station,” but also names KOIT, KEZR and Movin as direct competition. (Also in the Top 40 mix: KREV (92.7), the former dance music station, KNGY.

KKSF’s switch from smooth jazz to classic rock, says Parker, “has certainly resulted in shifts at KFOG. It’s less eclectic, and where they were more into singer-songwriters, now it’s more classic hits-based.”

Not so, says Lee Hammer, director of operations for Cumulus’ local stations. “We haven’t reacted to any other station.” “People have their own perceptions,” says Kelly Ransford, the station’s assistant PD and music director. “We’re playing the music we always do, we continue to do research and to cater to our audience.” “We’re always talking to our audience,” says Hammer, “to learn what’s right or wrong with what we’re doing.”

Meantime, at KKSF, which is challenging both KFOG and KSAN (“The Bone”), PD Dave Logan continues to widen and adjust his playlist, moving it beyond the initial concept of “legendary classics” to a broader sound, while dropping some softer cuts. (Seals & Crofts, anyone?) “To remain static,” says Logan, “is to assure your demise.”

What about in-house competition – like, say, KMEL and Wild 94.9, both Clear Channel properties? “They’re very different stations with distinct audiences,” says Parker. KMEL is hip-hop and R&B, attracting African Americans, Latinos, “everybody,” says Parker, including many women. “Wild” is considered more the “party” station, playing Top 40 and skewing slightly younger, with a solid white and Latino audience in the mix, according to Parker. “Wild’s” real competition, he says, is CBS’ “Movin,” which moved from what the industry calls “rhythmic adult contemporary” – a wide range of pop, R&B and dance music, minus rock – to Top 40. “That’s our playground,” says Martin. “Our target is women and their kids – 18 to 49. You want to grab as many people as you can.”

The programmers I spoke with tried to dispel the notion that music is programmed by some central committee, employing national research and computers, and dictated to local outlets. At KBLX, said Kevin Brown, PD and morning host, “all the music decisions are made locally,” and are determined “in large part by ratings, requests, music research and songs that music director Kimmie Taylor and I think are kind of cool and right for the station.”

That’s the trend, said Parker at Clear Channel. “What matters is what’s local.”

And what listeners want to hear.

This article appeared on page Q – 35 of the San Francisco Chronicle