Advice From a Hit Maker: Avoid Trends : Pop: Songwriters Expo panelist Diane Warren can name that tune because she probably wrote it.

Diane Warren excitedly changed stations on the radio in her cluttered songwriting studio in Hollywood. She stopped at the Milli Vanilli hit “Blame It on the Rain.”

“I knew I’d find one somewhere,” she said. Turning the dial again, she paused after hearing “When I See You Smile” by Bad English. Still another turn and Warren started to belt out “If I Could Turn Back Time,” her throaty voice chiming in with Cher.

“It’s amazing. At any given time these days, I can find at least one of my songs on the radio,” she said with a broad grin after finding three. “The other day I was driving and I found four on at the same time. I almost crashed the car.”

At 33, Warren is by most measures the most successful songwriter in pop at the moment. She wrote six of the top 100 songs on this week’s Billboard magazine singles chart and co-wrote a seventh (“Just Like Jesse James”--co-written by Desmond Child). That makes her the big name at this weekend’s Los Angeles Songwriters Showcase Expo at the Pasadena Convention Center.

A Showcase graduate, she will be on the “Hitsmiths” panel at 3 p.m. today.

Hearing her songs on the radio is nothing new to Warren, who has had 15 U.S. Top 40 hits since her first breakthrough, DeBarge’s “Rhythm of the Night” in 1985.

The bulletin boards she uses to keep track of projects past and present spotlight the varied artists who’ve benefited from her songs: Patti LaBelle, Aretha Franklin and Barbra Streisand, Chicago, Belinda Carlisle.

Warren grew up in the San Fernando Valley, dreaming of being a songwriter. “I was a radio addict when I was a kid,” she said, recalling the hours she spent listening to Motown records and the Beatles. “Those songs trained me.”

The radio was not the only thing that trained Warren. She started attending the weekly Los Angeles Songwriters Showcase meetings when she was 14. (The group--which sponsors this weekend’s expo--still holds weekly evaluation meetings, open to anyone, at 7 p.m. Wednesdays at Gio’s on 7574 Sunset Blvd., Hollywood. There’s a $7 charge for members, $10 for non-members. Information: (213) 654-1665)

“I would go there one night a week with about 10 songs, get shot down, and come back the next week with about 10 more,” Warren recalled. “But it was good because they were the first people I met that gave me feedback on my songs, and they helped me make connections.”

Warren still shows her loyalty to the showcase.

What does she tell her proteges?

“Not to quit. . . .

Another lesson is there is no such thing as a hot style to write in, so don’t limit yourself to trends. The thing is to write a great song which lasts forever. My job as a songwriter is simple, to write good songs. I don’t concern myself with hits. That’s not up to me.”

Warren writes in a range of styles but the more personal, sadder songs are her favorites. “I like to write from the heart about the heart, about people and relationships.” Her own long-term relationship is with record producer Guy Roche, who co-produced “If I Could Turn Back Time” with her.

Warren likes to keep the sentimental, romantic side of her personality hidden, but it comes through clearly in her songs. “In person, I’m sarcastic. I like to have an edge. Sometimes, people who know me can’t believe I can write these sensitive songs.”

LIVE ACTION: Tickets are on sale for Concrete Blonde’s show at the Palace on Dec. 1. . . . Hard-rockers Badlands and D.A.D are also at the Palace, on Dec. 15. . . . Exene Cervenka will be at Bogart’s in Long Beach on Nov. 24 and the Coach House in San Juan Capistrano on Nov. 25. . . . McCabe’s is hosting a benefit for Santa Cruz earthquake relief on Nov. 11. Performers will be announced as they’re confirmed. . . . Bill Medley is also taking up the earthquake cause, performing a benefit show on Sunday at the Righteous Brothers’ Fountain Valley Hop. . . . k.d. lang’s postponed show at the Ventura Theatre will be held Nov. 22, while her date at the Celebrity Theatre in Anaheim has been rescheduled for Nov. 28.