Stretching the bluegrass boundaries farther than ever before, Hardly Strictly Bluegrass kicked off its weekend run with a Friday morning educational program featuring a rap and break-dance performance by pioneering hip-hop artist M.C. Hammer. Several thousand students from San Francisco middle schools responded to the feel-good performance with more exuberance than they might have for a pure bluegrass set, even though Hammer might have been as "old school" and before their time as, say, Earl Scruggs.

Hammer addressed the elephant in the meadow, saying he had been asked what he was going to do at a bluegrass festival. As the bass-heavy groove started up, he yelled the title of one of his hit numbers, "I'm gonna turn this mother out." Crowded on the periphery of the audience (outside the fenced-off kids-only center section), a robust crowd of young adults who had come of age with the Oakland-based Hammer in the 1980s and '90s, chanted along.

The 45-minute set featured some eye-popping dance moves, as two troupes of break-dancers took turns swirling around the hip-hop star. Since dance is an important part of bluegrass and old-time music, traditional bluegrass fans in attendance had to have been impressed with the fantastic dancing, whatever they may have thought about the genre-bending music.

They may have been more excited by the program's opening act, 14-year-old fiddler and country singer Ruby Jane Smith, who performed an impressive set of bluegrass, rockabilly and country songs. Presenting a youthful bluegrass act is part of the Friday programming formula, apparently meant to inspire interest in acoustic music among the students. Ruby Jane worked hard to engage the audience, and seemingly succeeded in getting some to dance and sing along.

It was the first I had seen of the talented Austin-based musician, who also performs with Asleep At the Wheel and had two of their members playing backup. The highlight of the set was a new original rockabilly song, "Greasy World," with clever lyrics and a great hook. Festival talent bookers should keep their eyes out for this emerging talent.

Festival benefactor Warren Hellman was much in evidence during the program, joining Ruby Jane for a banjo turn on "Soldier's Joy," and speaking directly to the kids several times. At the end, he asked the audience if they'd want to have Hammer back next year, and got an encouraging cheer. I suspect that Hammer Time could become a permanent fixture for the Friday program at future festivals.

The event is a tie in to Daniel Pearl World Music Days, an international music education program that honors the late journalist who was killed in Pakistan in 2001. The public school kids boarded buses and headed back to school for the rest of the day, but an hour later I saw that one private school class had moved to the banjo stage to get ready for the afternoon program, gathered in a group around their earnest teacher discussing their festival experience.

Bravo! That's the way to start them young.