LONDON — Andrew Lloyd Webber announced Thursday that actor David Fynn and 39 “quite awesome” kids will star in the London production of stage musical “School of Rock ,” using the occasion as a cue to urge the government to maintain funding for school music programs.

Fynn, the British star of NBC sitcom “Undateable,” has been cast in the lead role of Dewey Finn, a rocker-turned-substitute teacher who forms a classroom rock band in the show based on the 2003 Jack Black movie of the same name.

He’s joined by a cast of youngsters ages 9-13 who sing and play their own instruments.

At the production’s official launch Thursday, Lloyd Webber said “the depth of the musical talent that we auditioned is something that I have to admit that I didn’t think we’d find immediately.”

“It’s just incredible to think that these kids are playing this sort of music,” he said. “I kind of feared that everybody would be all into their computers and that they’d be doing all of this programmed music.”

Lloyd Webber said the U.K.’s deficit-slashing government should keep funding music programs, because “every penny you spend on music in schools comes back twenty-fold.”

The head-banging musical has a surprisingly strong link to the British Parliament’s House of Lords, whose members sport aristocratic titles and wear fur-trimmed scarlet robes on ceremonial occasions.

Both Lloyd Webber, whose title is Lord Lloyd Webber, and book writer Julian Fellowes — Lord Fellowes of West Stafford — are Conservative members of the Lords.

Fellowes, who wrote aristocratic drama “Downton Abbey,” said the two men “did have one of the early meetings about the whole thing in the House of Lords.”

“This is what happens when peers get together: a rock musical,” he added.

And he joked: “I would have thought after ‘Downton’ it was a natural fit.”

“School of Rock” opens at the New London Theatre on Nov. 14. A New York production that opened last year and notched up four Tony Awards nominations is still running on Broadway.