"Ageism isn't quite the barrier to women that it is in movies, where youth is the only currency that's viable," he said. "In the world of rock 'n' roll, getting down and dirty, you don't have to still be quite as gorgeous as long as there's verve and charisma."
Still, some younger fans worry about that verve when these rockers hit their seventh decade, possibly agreeing with Grace Slick's own convictions about aging performers.
"A sense of perspective is more valuable than Botox or other methods of wishful arrested development," said New York City musician Alex Clifford, 24. "So we don't have 70-year-olds preening around onstage pretending they still have it."
Today, Slick has transitioned gracefully from '60s rock icon to artist. Her "Wonderland" series of fantasy paintings are, in some ways, an homage to her days as the queen of psychedelia.
Her musical tastes, though classic, are more masculine -- Sting, Peter Gabriel, "American Idol" winner David Cook and the Gypsy Kings. Though Slick still has a strong voice, she refuses to sing publicly again.
"Rock 'n' roll is for young kids," Andrea Cagan, who co-wrote Slick's 1999 memoir, "Somebody to Love," told ABCNEWS.com. "Grace knows these stars make hundreds of millions of dollars, but it's incredibly embarrassing to see older people flapping their cellulite around stage."
Slick is equally disparaging of the crowds that flock to those concerts: "Whoever can show up without being wheeled in with an oxygen tent," she said. "People try to relive what their youth was like."
The self-described "fat, white-haired" Slick, who can at once swear like a sailor and purr like a grandmother, said she has no regrets about her career.
"The only thing you regret when you get old is what you didn't do," she said in her warm, husky voice. "I regret I didn't nail Jimmy Hendrix or Peter O'Toole, Richard Harris or Richard Burton. I missed out drinking and whooping with the British guys."
Brad Martin contributed to this report.