When Charlie Stemp signed his contract for the West End transfer of the musical Crazy for You, one of its conditions was an ice bath in his dressing room. “The producers were amazing,” he says, and tells of how the Gillian Lynne theatre had to be refurbished to get it in. It was not, as it sounds, a diva-like demand akin to a bathtub of orange Smarties. It was vital to his high-energy turn as wannabe dancer Bobby – a part that requires him to be on stage for the majority of the musical, dancing everything from ballet to tap to modern. He dazzled in the role during the musical’s original run at Chichester festival theatre, and the ice bath saw him through it. “I need to ice my muscles after the show,” says Stemp, fresh-faced after a morning’s rehearsals at the studios of English National Ballet. In the lead-up to its opening in Chichester, he worked six days a week over six weeks to get his part to its polished state. On top of that, he was performing in the West End’s Mary Poppins every night. That’s where the ice bath proved invaluable. “Without wanting to show off too much, it’s the equivalent of an athlete – like a footballer – icing their legs after a game, we have to do the same. Because my role is quite heavy I’ll have an ice bath for 10 minutes. It just gets the blood flowing around your body.” If the bath was key for winding down, revving up has never been a problem, he says, nor running in fifth gear. Stemp, in fact, speaks of having an “unimaginable” amount of energy. “I’ve never sat still. If I’m tired, it’s even more so. Alan, who is the conductor of the show, always says to me, ‘I can always tell when you’re tired because you get faster.’” Susan Stroman, who choreographed the original production of Crazy for You in 1992 and is also directing this revival, shaped the dance routines around Stemp’s abilities. “She has been so great at seeing my energy and incorporating it into the show. She said, ‘Let’s change the show to cater to my strengths.” Four months short of his 30th birthday, Stemp has distinguished himself as a rare talent in musical theatre, garnering Olivier award nominations for his performances in Half a Sixpence and Mary Poppins, and earning comparison to Fred Astaire. He tries not to watch the film of the show he is in, where there is one, especially if he’s playing a role made famous by another actor. But Bert was another matter: he grew up idolising Dick Van Dyke in the role and knew Mary Poppins inside out. “He’s the reason I started performing. My mum used to tell me off for putting the broom up the chimney.” Stemp knew early on he wanted to perform. “I grew up watching Norman Wisdom movies with my granddad,” he says, and later, Lee Evans. “When I’m on stage, I’m often trying to make people laugh.” Born in London in 1993, he was a fantastically active child who loved football, rugby, judo. “Dancing was another outlet for releasing some of the energy.” It took over, and the original dream was to work for Matthew Bourne, but the journey into professional dance wasn’t made easy for him. “The British school system is not very accommodating for boys who want to do dance. I wasn’t allowed to do dance GCSE. If a school says boys can’t dance, what are boys who like dancing expected to do?” That gendered prejudice is still widely ingrained today. “I have conversations with dads of young boys who say of their sons’ dancing, ‘We’ll stop him soon and football will be the next thing.’ But we’re sitting at English National Ballet – and the energy and strength that the boys need in these rooms surpasses that of a football player, without question.” Stemp was a big, loud personality and began to show signs of upset at the school, where he was marked out as different. Thankfully his mother heard about a local theatre school, Belcanto Academy, and enrolled him. He thrived, but would still change out of his dance clothes after classes so he wasn’t mocked on the way home. “Of course I couldn’t get a bus in my ballet tights. Now I’d do it with pride, but fitting in when you’re that age is so important. Everyone’s journey is different – mine will not be as painful as some other men’s.” He got a scholarship to Laine Theatre Arts in Surrey, and his first job, aged 20, was as Monkey No 3 in Wicked. He has worked on musicals ranging from an international tour of Mamma Mia to Broadway’s Hello, Dolly! Looking out from these stages, he has an actor’s eye view of audience behaviour – which is a subject that has hit the headlines in recent times. He has asked people to put their phones away while in character, and occasionally resorted to more radical interventions. “If you get your phone out, I’m going to lose it. It’s so rude. But I see it every show. I got into so much trouble once. We were in Greece with Mamma Mia, in the final dance position, and someone had their phone right in front of me. So I just grabbed it and went off the stage.” Stemp thinks responsibility does not lie with audiences alone, though. “It’s up to producers and management to make it clear before the show starts that it’s not appropriate to sing, or to do this or that. We have to help guide audiences because otherwise, if you have gone to a jukebox musical like Mamma Mia and sung every song and then go to The Bodyguard, for example, why wouldn’t you think you can do that there too?” In the case of the latter show, the antisocial behaviour was clearly fuelled by drunkenness, adds Stemp, which he also sees a lot. “My job is to try and make this the most perfect show I can. As soon as someone else is affecting that, it is the most infuriating sensation, because there’s not much I can do.” Beyond Crazy for You, are there roles he has his sights set on? “All of them,” he says, and then, “To be honest, whatever roles come my way, as long as I’m happy.” Would he still like to work with Matthew Bourne? “Yeah, as long as I get my ice bath.” Crazy for You is at the Gillian Lynne theatre, London, from 24 June to 20 January