"He said, 'Give me a few days.' But, Ben being Ben, he went out for a walk in the park and wrote it all in a night," May said. "He came up with this idea about kids in the future who do not know what rock 'n' roll is. It's deceptively simple, but there are rather subtle layers to it."
The scenario, set 300 years from now, envisions a world where young people look and think the same way and listen exclusively to music pre-approved by a mighty corporate entity. That music doesn't rock. Making your own is impossible, since all instruments are banned.
None of this sits well with some misfits known as the Bohemians, especially a guy called Galileo and his girlfriend, Scaramouche, who seek to revive the rock they've heard of and set out to find a legendary guitar that will help them.
"A story about humans spoon-fed and controlled by marketing — that's relevant," May said.
The show got a tryout at a 2001 workshop in London attended by De Niro, who signed on as one of the producers, via his New York-based company Tribeca Productions.
The final version of "We Will Rock You" opened the next year at London's Dominion Theatre, where a large statue of Freddie Mercury, in full performance mode, now stands above the marquee.
"When the show opened, it was crucified by the critics," May said. "We would have closed in a week if it hadn't been for a couple of TV appearances where people could see what the show was like. Ticket sales took off. That was 11 years ago, and it's still rocking. Every time I drive past the Dominion and see Freddie's statue, I stick a finger up."
There's a statue of Mercury onstage in the musical, too, providing a little biographical touch after all. It adorns a venue where the Bohemians hang out.
"They regard him as a messiah almost," said Ruby Lewis, who plays Scaramouche in the new touring production. "They worship Freddie for what he was in history, someone who changed the face of rock 'n' roll. The show pays homage to him by name. Brian and Roger loved him so much."
Mercury's personal life and death are not subjects for the musical.
"It's a comedy," May said. "It's pretty light. There are a few jokes about various aspects of all of us that are funny."
For the North American tour, some tweaking of the original text has been done, mostly to avoid Brit-isms that might not be understood. No need to fiddle with the music, of course; it has been reaching across boundaries and age groups for decades.
The Kentucky-born Lewis demonstrates that point. At 28, she is too young to have experienced Queen's heyday firsthand, but she practically grew up on the band.
"My parents were big classic-rock fans," she said. "They played Queen on the record player almost every night. I would dance to 'Another One Bites the Dust,' and a friend and I made up a dance for 'Bohemian Rhapsody.' The music never sounded dated to me. Being in this show is so surreal for me."
As for all the stage action woven between the Queen hits in "We Will Rock You," Lewis finds it persuasive.
"The story serves the music really well," she said, "and there is a lot of smart humor and tongue-in-cheek stuff. Teenagers are going to laugh, as well as adults. It's so fantastical. It takes you on an almost Jim Henson-y journey. As long as people aren't going to dissect it as a piece of Shakespeare, I think it will come off well."
Her role in the musical gives Lewis a direct connection to Queen's famed guitarist.
"Scaramouche turns into Brian May incarnate," she said, "so I have to look like I'm playing a major guitar riff."
The actual musicians in each staging of "We Will Rock You" are personally auditioned by May and Taylor to ensure an authentic sound.
They both have remained involved, in one way or another, with the band that brought them fame. They relaunched Queen in 2005 with Paul Rodgers of Bad Company and introduced another version last year with Adam Lambert of "American Idol."