While the casting was under way, music supervisor Randy Poster, who had worked with director Richard Linklater previously on "SubUrbia," set out to build a musical team. The first thing he did was to bring in a ringleader for the kids Jim O’Rourke, who produces and plays with Sonic Youth.
"One of the great advantages of this movie is that we had 10 weeks where we basically put the kids in rock-and-roll boot camp," says Poster. "In that way both before and during production the kids became very comfortable with their instruments and all aspects of the story."
Jack Black was glad to see Jim O’Rourke on board to help his young costars prepare for their roles and truly have a good time during the entire filmmaking process.
"Jim is a great musician, a good producer, and he even has some albums out on his own," observes Black. "He rehearsed with the kids till their chops were really up and their rock licks were nice and shimmy-shammied."
O’Rourke. who in addition to performing with Sonic Youth has produced for the bands Stereo Lab and Wilco, explains that first he needed to find out what the kids could do before he knew exactly what areas each had to work on.
"I needed to find out what they were used to playing, what style they liked to play in and what theii’ strengths and weaknesses were," says O’Rourke. "After I gathered that information, it was my job to make it all blend."
According to Craig Wedren, who composed the film’s instrumental score and jammed with the kids during numerous band rehearsals, the set truly turned into a music camp and a safe haven for the kids to just rock out. "It took me back to when I was 12 years old and in my first band," recalls Wedren. "It was a time you could just wail on your guitar or bang on your drums and make great music with your friends, and that’s what happened on the set with these kids."
Joey Gaydos Jr., the lead guitarist, remembers when they began rehearsals. "The first time we actually played together, we were real sloppy, you know, because it was our first time," admits the 12-year-old. "But when we began really practicing, we started to sound pretty good."
While some kids were already familiar with the style of music they were going to play in "The School of Rock," others were not. Twelve-year-old Robert Tsai, for example, who had been playing the piano since the age of five, was strictly a classical musician.
"Robert didn’t really know anything about rock music, so when rehearsals first began it was quite a mystery to him what we were doing," remembers O’Rourke. "I’d put a piece of sheet music in front of him and he’d play it, but always in a very classical style. In the end, though, he was jamming with the rest of us."
Rebecca Brown got into the swing of things, too. A guitar player since the age of four, the 11-year-old not only learned how to play bass guitar for the film, but she also had her first introduction to the cello, which she plays in the Horace Green Elementary School orchestra.