The names and photos on these gleaming trophies — Anastacia, Mariah Carey, Kelly Clarkson, Color Me Badd, Celine Dion, Whitney Houston, Al Jarreau, Elton John, 98 Degrees, Jessica Simpson and Barbra Streisand, for starters — reflect the international success racked up by Novato musicians and songwriting-producing partners Louis Biancaniello and Sam Watters, individually and together, over the past 15 years.

Their most recent claim to fame is "I Believe," the debut single by 2004 “American Idol” winner Fantasia Barrino, which was recently honored with a Billboard Music Award for top-selling single of the year and remains the biggest-selling CD single thus far this year. The song is on the singer’s first album, "Free Yourself," released last month on J Records.

The flood of producing assignments became so hectic that Biancaniello and his wife and two kids moved out of the house two years ago and bought another one in Novato. Living and working in the same space did have advantages, however.

"Jessica (Simpson) actually did my daughter’s hair for her homecoming dance in high school," says Biancaniello, 47. His son Michael, 13, still stops by the studio from time to time, and even contributed a rhythm guitar part to a song on former "American Idol" contestant Tamyra Gray’s album.

Biancaniello and Watters began writing and producing together seven years ago. A classically trained pianist born in Pleasantville, N.Y., Biancaniello landed his first recording contract at age 9. He and his older brother had high hopes for the Tidalwaves, a pop-rock band modeled on the Beatles and Dave Clark Five, but the one single they cut in New York City for Mercury Records was shelved. He moved to San Mateo with his family after high school and began working as a Bay Area club musician, eventually handing a job as musical director for cross-dressing San Francisco disco diva Sylvester.

Watters’ first record, in contrast, was a smash. "I Wanna Sex You Up," which he co-wrote and sang as a member of the Oklahoma City harmony quartet Color Me Badd, shot to No. 2 on Billboard’s pop singles chart in the summer of 1991. The group’s debut album, which also contained the hit "I Adore Mi Amor," sold 6 million copies, yet Watters, now 34, says he realized little money for his efforts.

"We really got ripped off," he says. "It was a bigtime learning experience." Color Me Badd, which started in 1984 as a high school a cappella group, struggled on before breaking up in 1998.

Watters first hooked up with Biancaniello in 1996 when Color Me Badd came to San Rafael to record with producer Narada Michael Walden. Biancaniello, who’d arranged and played on such Walden-produced hits as Mariah Carey’s “Love Takes Time” and Whitney Houston’s "I’m Every Woman," impressed Watters with his work on the Color Me Badd album. Their early collaborations were done by mail — Biancaniello was in Novato, Watters in New York when they wrote the Simpson’s 1999 hit "I Wanna Love You Forever" — but Watters soon moved to Novato.

Although they’ve scored big in Europe with dance tunes for American-born, Tina Turner inspired vocalist Anastacia, the two men are best known for inspirational power ballads that reflect their mutual love for African American gospel music, Fantasia’s “I Believe” being the latest.

Biancaniello and Watters had just begun separate vacations when "American Idol" producer Simon Fuller flew them to Los Angeles to create a song for this year’s three finalists. The producers, in collaboration with Gray, wrote "I Believe" for Jasmine Trias, Diana DeGarmo and Fantasia to perform in the competition, though they admit they had Fantasia most in mind.

"Fantasia is astounding," Watters says. "Usually, Louis and I will take singers for hours and hours to get a great vocal down — sometimes days — but she came in there and made the record in 40 minutes and just blew us away. It wasn’t like she went in there and sang allout soul-gospel. She also got on the verses and gave it what they needed, which was a little bit more beauty, a little bit more restraint."

Biancaniello and Watters recently spent two weeks in London producing a number of vocalists managed by Fuller, whose popular British television show "Pop Idol" was the model for "American Idol." They included Emma Bunton, who was known as Baby Spice when she was a member of the Fuller-created Spice Girls.

Back in their Novato studio, they’ve been working on material for debut albums by two women who are not particularly well known for their singing — actress Lindsay Lohan (her "Speak" CD was released in early December) and hotel heiress Paris Hilton. Such projects offer challenges different from those of working with vocal virtuosos like Fantasia and Celine Dion.

"We start from scratch each time," Biancaniello explains. "It’s really a different project with each artist. You know, Fantasia is an incredible gospel singer, so we would create that kind of environment, but someone who is a less experienced singer needs something that’s maybe more vibey and maybe has a melody that’s easier to sing.

"We try to make the song and the production work for an individual artist, tailor the track — as well as the melody, the lyrics and everything — to enhance their good points. What makes them shine is what we’re trying to bring out."