Ani DiFranco, Maceo Parker Together Onstage

She introduces new songs, including one reflecting on the Colorado high-school shootings.

BERKELEY, Calif. — Folk singer Ani DiFranco played a handful of unreleased songs and mixed it up onstage at the Greek Theater with funk veteran Maceo Parker on Friday night during a stop on what the two performers are calling the F-Word tour.

Playing together during one another's sets, they seemed to convince the audience at the outdoor amphitheater that the tour is actually about two F words: folk and funk.

DiFranco joined saxophonist Parker's band for Sly and the Family Stone's good-time anthem "Sing a Simple Song," and Parker later returned the favor, joining headliner DiFranco for her encore, "Overlap."

"To see two styles of music like that come together — they're both about that," Kendra Southman, 23, of Oakland, said. "They love music, they love performing, they love their audience ... I've seen Ani DiFranco play a few times, but I'm a big Maceo Parker fan. I probably wouldn't have come to the show if he wasn't here. It's too much of a trip to miss, you know?"

The politically minded DiFranco, 28, introduced songs reflecting on the April high-school shootings in Littleton, Colo., and the October 1998 shooting of an abortion provider, Dr. Bernard Slepian, in Amherst, N.Y., which is a suburb of DiFranco's hometown, Buffalo. She also played several songs from Up Up Up Up Up Up (1999) and a few early favorites.

Along with the requisite T-shirt stand were tables from Planned Parenthood and Earth Justice Legal Defense Fund. A portion of the show's proceeds were slated for the Seva Foundation, which funds eye-care hospitals in South Asia and nutrition programs to combat diabetes on American Indian reservations.

Parker, a longtime fixture of James Brown's JBs, and who also served a stint with another seminal funk group, Parliament/Funkadelic, set the tone with a 45-minute set including tunes from his latest album, Funk Overload (1998), and JBs classics.

As the sun set over the classical-style amphitheater, 56-year-old Parker, in a sharp, black suit that betrayed his old-school showman aesthetic, led his band in a slow and heavy "Pass the Peas."

At the core of the performance was the interplay between Parker — who also has recorded with Jane's Addiction, Deee-Lite and De La Soul — and trombonist Greg Boyer. It evoked the definitive funk-horn style Parker developed with trombonist Fred Wesley in the JBs.

After quoting Parliament's "Up for the Downstroke," Parker announced, "For those of you who do not know, everything from now on is gonna be funky!"

His son, Corey, stepped up to rap on "Uptown Up," from Funk Overload. As the band began another slow groove, Parker told the audience he had done a talent search in Berkeley earlier that day to find a female singer. As the "winner" stepped onstage, the crowd went wild — it was DiFranco, wearing a necktie to match the dapper Parker.

Parker sang "I'm walkin'," and DiFranco replied with "I'm talkin'," hitting the low notes, to the crowd's delight. That exchange led into Sly and the Family Stone's "Sing a Simple Song." DiFranco even did some choreographed dance moves with the band.

Taking the funk cue from Parker, DiFranco started her set with an electric-flavored "Virtue" (RealAudio excerpt), from Up Up Up Up Up Up. As pot smoke wafted through the summer night air, DiFranco strummed her acoustic guitar in her signature slap-pop style, and her band stayed right with her syncopation.

"Welcome to our winter wonderland," DiFranco said, referring to the chill in the evening air. "Let me introduce you to my friends, whose nipples are also erect," DiFranco continued, motioning to bassist Jason Mercer, drummer Darren Hahn and keyboardist Julie Wolf.

The folk singer improvised lyrics frequently, talking about a topic, then incorporating it into a song.

"As you can see, there's some people here filming on behalf of a human behavioral study," DiFranco said, referring to her own film crew. "They're investigating the effects of massive amounts of funk and folk music on very cold people."

After "Two Little Girls," from Little Plastic Castle (1998), DiFranco played a new song, "Providence," in which she rapped, "I've just got one thing to tell you/ That words are vitamins and life is short."

In another new song, "Hello, Birmingham," about the murder of an abortion doctor, who was shot through his kitchen window, she sang, "A bullet ensuring the right to life/ Whizzed past his kid and his wife/ And knocked his glasses right off of his face/ And the blood poured down the pulpit."

DiFranco reached back to Puddle Dive (1993) for "Willing to Fight" (RealAudio excerpt) and "My IQ," about taking an IQ test as a little girl and being told that "different is wrong."

Yet another new one, "To the Teeth," derided the U.S. gun culture: "The sun is setting on the century/ And we are armed to the teeth," DiFranco sang, "And every year now like Christmas/ Some boy gets the milk-fed suburban blues/ Reaches for the available arsenal/ And saunters off to make the news."

For "Not So Soft" (RealAudio excerpt), DiFranco stripped down to a tank top to play a hand drum between her knees, as her whole band played percussion instruments. "I always wanted to be commander-in-chief of my one-woman army," she sang, and her audience responded by clapping in time.

DiFranco brought up Boyer for "The Diner" and a ska-inflected take on "Anticipate." Corey Parker came out to rap for racial unity during "Jukebox."

The crowd fell silent as DiFranco brought Maceo Parker out for her encore, "Overlap," from 1994's Out of Range. She sang to her adoring audience "Stand here in front of the light stands/ So I can see your silhouette/ 'Cause I am not done looking at you yet."

It was the first DiFranco show for Kristen Myles, 17, from Walnut Creek, who said she has been a fan for four years. "Ani was hell of cool," Myles said. "It's so much better to hear it live than on the CD, because you know that it's her; she can sing ... [Maceo was] cool, but Ani was best."