Oldies radio stations around the country are debating whether to continue playing the music of one of the quintessential '60s groups, the Mamas and the Papas, in the wake of Mackenzie Phillips' allegations that she had an incestuous relationship with her father, group founder John Phillips.

"I just had a long discussion with our morning show team," said Jay Beau Jones, program director of Boston's WODS, "Oldies 103.3," a long-running CBS Radio affiliate. On Friday morning, disc jockeys Chris Zito and Karen Blake will invite their audience to call in and talk about Phillips and his musical legacy. "Obviously, this is a horrific, car-crash type of story," says Jones. "If the station plays 'California Dreamin'' or 'Monday, Monday,' my concern is the audience will have a negative reaction and turn off the radio."

In contrast, Dan Allen, creator of Clear Channel's "Real Oldies" format, says he doesn't anticipate any lasting boycott of the band's music. "If we stop playing them, who are we going to hurt?" he says. "I don't think we can punish John Phillips," who died in 2001.

If true, Allen adds, Mackenzie Phillips' claims are "abhorrent. I have two daughters myself. But I don't think it's going to cause a backlash."

After giving PEOPLE magazine excerpts from her new memoir, 'High on Arrival,' Mackenzie Phillips appeared on 'Oprah' and 'Today' this week, repeating her claim that her father raped her while both were under the influence of drugs, and that the two had intermittent sexual relations during the next 10 years.

"My father abused me, but he wasn't a monster," she writes. "He was a tortured man who led a tortured existence."

John Phillips, the son of a hard-drinking ex-Marine, grew up in Alexandria, Va., breaking into music on the folk scene of New York's Greenwich Village in the early 1960s. With two fellow folk veterans, Canadian Denny Doherty and Baltimore product "Mama" Cass Elliot, and a young Californian named Michelle Gilliam -- who would become his second wife -- he started the Mamas and the Papas. The folk-rock quartet's combination of exuberant group vocals, saloon-style piano and lush arrangements by some of the West Coast's best session musicians, led by drummer Hal Blaine, made the group a key part of California's emergence at the center of the pop world.

Phillips was instrumental, along with producer Lou Adler, in the creation of the Monterey Pop Festival in 1967, which introduced the Who, Jimi Hendrix and Janis Joplin to the American mainstream. He wrote and produced the Summer of Love anthem 'San Francisco (Be Sure to Wear Flowers in Your Hair),' recorded by his colleague Scott McKenzie, with whom he would co-write another huge hit, the Beach Boys' 'Kokomo,' in 1988.

Scoring 10 Top 40 hits in two years, the Mamas and the Papas had a notoriously rocky relationship behind the scenes. Phillips wrote one of the group's biggest hits, 'I Saw Her Again,' in response to Michelle's affair with Doherty (which, curiously, Doherty sang lead on).

After decades of heavy drug use -- Phillips once claimed he injected himself with cocaine and heroin every 15 minutes for two years -- "Papa John," as he titled his autobiography, had a liver transplant in 1992. He died at age 65 in March, 2001.

Sainthood is not exactly a prerequisite for election to the Rock and Roll Hall of Fame, as the Mamas and the Papas were inducted in 1998.

"We don't have any problem playing music by other people who have done heinous things," says Clear Channel's Allen. "Rockers 'n' rollers aren't always good boys."

Even so, few rock 'n' roll images have been tarnished quite as badly as John Phillips' this week.

Michelle Phillips, the bandleader's second of four wives, said this week that she does not believe her stepdaughter's allegations.

"Mackenzie has a lot of mental illness," she told the Hollywood Reporter. "She did 'Celebrity Rehab' and now she writes a book. The whole thing is timed." (However, Michelle's daughter, Chynna Phillips, has stated she believes her half-sister Mackenzie's allegations.)

Cammy Blackstone, a longtime on-air personality on San Francisco's KFRC who now works at San Francisco City Hall, had a similar reaction. Having interviewed Mackenzie Phillips on the radio, she wonders why the former child star of the '70s sitcom 'One Day at a Time' would feel compelled to divulge her story now.

When Blackstone was on the air, there were numerous episodes involving core Oldies artists -- Phil Spector's murder case, James Brown's domestic problems, accusations of child molestation against Michael Jackson and Gary Glitter. "I don't recall any listeners every calling and saying, 'Why are you playing that child molester?" she says.

WODS's Jones also wonders where program directors should draw the line when it comes to unsavory news about popular artists: "Do you stop playing songs by Phil Spector or Elvis? Maybe our listeners want to hear 'California Dreamin'' and remember the Mamas and the Papas as the hit machine they were. We said, 'Let's let the audience decide.'"

Radio corporations do tend to reassess their playlists when news stories break, says Blackstone. "After 9/11, we didn't play 'Great Balls of Fire' or 'You Dropped a Bomb on Me.' You do have to be considerate about people's emotions over what's happening in the news."

But in the case of the Mamas and the Papas, although John Phillips was the group's acknowledged mastermind, most listeners aren't likely to "make that connection," says Blackstone. "It's the song more than the group."

Allen agrees. "The face of the Mamas and the Papas without a doubt was Mama Cass," he says. "And she did nothing wrong."