You could almost feel it thumping as it sat outside Sequoia High School in Redwood City on Saturday morning: a 45-foot-long, diesel-powered, multimedia wizard's laboratory on wheels.

And inside the John Lennon Educational Tour Bus, a 15-year-old nonprofit audio and video recording studio with 750,000 cross-country miles under its chassis, a clutch of wizards was hovering over a bubbling cauldron of creativity. On the glowing computer screens, there were drum tracks layered over keyboards and guitars, a chorus of high school girls and the hopeful rapping of Sequoia senior Alejandro Castro.

"We can change the world one day at a time,'' Castro chanted over and over. "You play your part, and I'll play mine.''

Later this week, the as-yet-untitled song will be unveiled as part of a music video during an appearance by U.S. Secretary of Education Arne Duncan, who will be in Silicon Valley to kick off his own cross-country bus trip heralding a hopeful start to another school year in America. But Saturday morning, the handful of students involved in the Lennon Bus project looked on as the head wizard -- songwriter and record producer Printz Board, musical director of the Black Eyed Peas -- did his magic.

"It is so cool to work with these young people, to hear a young guitarist or one of these girl singers who are so amazing but still too young to even know it,'' said Board, who turns 30 on Tuesday and has worked with the Lennon Bus since the late 1990s.

Karen Cator, director of educational technology for the U.S. Department of Education, stood inside the bus Saturday as Board and other engineers fiddled with dozens of dials, tweaking the rap song into perfection. She said the department had reached out to the Lennon Bus after Sequoia was chosen as the kickoff site for the secretary's third annual back-to-school bus tour, this time crossing the country for the first time.

"We wanted to kick off the event, Education Drives America, in Silicon Valley because it's such a center of entrepreneurship and innovation," Cator said. "And we'll use the students' music video to shine a spotlight on them and on a hopeful new school year.''

The song's lyrics brim over with upbeat lines like "now is the time, we are the future,'' repeated over and over by a high school chorus of Joselyn Juarez, Alicia Menendez-Brennan and Jackie Ahern.

Castro's rap punctuates the piece, while the guitar solos of Sequoia senior Jared Solomon soar high above the voices. Black Eyed Peas guitarist George Pajon Jr. also volunteered his services, flying up from L.A. to work with Solomon and the other young musicians, who seemed a bit awestruck from being able to work with a huge star like Pajon.

"We all threw out some musical ideas at first on Friday, then took turns on solos,'' Solomon said. "And it all came together here on the bus. I've never worked with pop artists before, because I'm like anti-that. But this was so cool to watch the whole music-video production process. My time on the Lennon Bus has made me appreciate pop music.''

Castro agreed. "We're all young, and we are the future,'' he said. "And we love this bus. It's amazing how everyone works together here to make something they love.''

Pajon said he, in turn, was blown away by the collaboration with young talented musicians.

"Overwhelming,'' he said. "So much musical knowledge, at such a young age. It's really inspiring to me.''

Pajon said that when Board asked him to join the music-video project, he jumped at the chance to take a break from working on his own solo album, due out in two months. In a way, it was just another chapter in a longtime love affair he's had with the bus, its crew and its musical mission.

"We've been involved with the bus guys since 1999, and they've been really inspiring to us over the years,'' Pajon said. "This was a welcome break for me. I could use a dose of inspiration, and it's been absolutely great to see young creative minds at work here.''

Contact Patrick May at 408-920-5689 or follow him at Twitter.com/patmaymerc