Lesson one: Andrew Lloyd Webber is the father of rock musicals.

Once that simple thesis is posited, the whole genesis of School of Rock–The Musical suddenly makes perfect sense, despite a creative team that includes the creator of Downton Abbey, the director of Les Miserables, and the lyricist behind the Broadway versions of Sister Act and The Little Mermaid. But rock is hardly about what’s on the surface, anyway.

“I always remember [The Who’s] Pete Townshend saying to me that the guitar playing in Phantom of the Opera is as rock as anything he’d ever heard,” Lloyd Webber tells EW. For all of Webber’s Cats and Technicolor dreamcoats, the theater composer largely invented the rock musical form with his seminal rock opera Jesus Christ Superstar in 1970, followed by 1984’s Starlight Express, and 1989’s Phantom. “Sometimes people have a problem with me because they like to compartmentalize, but I’ve got many sides and love all different types of music. [In writing School of Rock] I went back to a lot of my old roots, and I listened to what Jack Black did with Tenacious D, but I didn’t say ‘I’m going to revisit all my old Zeppelin albums.’ Because I’ve never not listened to them, really.”

Webber’s headbanging heritage makes him an adroit choice, then, to shepherd a Broadway stage version of School of Rock, the 2003 comedy starring Jack Black as a schlubby fake substitute teacher who transforms a class of prep-school kids into the rock band he never had. Rock is in Webber’s blood, as the show’s leading man and fellow music superfan can attest.

“Jesus Christ Superstar is the rock musical, and Andrew Lloyd Webber is a proper rock dude,” says Alex Brightman, the 28-year-old newcomer who bopped around Broadway ensembles before assuming Black’s role in the production, opening December 6. “Andrew loves Metallica, Megadeth. He was a British kid that f—ing listened to AC/DC. It’s just his thing.”

Image zoom Matthew Murphy

After landing the rights from Paramount Pictures, Webber found a kindred rock spirit in director Laurence Connor, with whom he was collaborating on an arena tour of Jesus Christ Superstar; lyricist Glenn Slater, who had worked with Webber on his Phantom follow-up Love Never Dies; and book writer Julian Fellowes, whose sensibility writing for the wealthy elite — he created Downton Abbey, to wit — provokes a similar reaction of surprising harmony with the project, once you give it enough thought.

“I did get my first break writing children’s drama at the BBC, actually,” says Fellowes. “I was so delighted with School of Rock because I can’t think of anything further away from Downton Abbey if I tried. I’m happy with typecasting but on the whole, it’s fun to get out of your own straightjacket sometimes.”

In the show’s Main Stem debut, Webber and his team also found a cast of over a dozen talented tweens who play their own instruments (and, importantly, their own age) and elevate School of Rock from a cut-and-dry movie-musical adaptation to its own rousing theatrical experience.

“When a 14-year-old kid has long hair and eye make-up and is rocking out, it just seems less impressive, but when you see an 11-year-old boy who’s still at the point of being able to believe in Santa Claus and he picks up a guitar and shows you this amazing skill, you simply can’t help but be totally impressed by that,” says Connor.

Watch EW’s exclusive sneak peek at the kids, the adults, and the man-child at the center of it all in School of Rock the Musical.