If the sheer number of summer festivals these days is such that music fans are beginning to tire of them, then spare a thought for the artists, required not merely to perform at Reading and Glastonbury, V and Bestival and all the rest, but also their equivalents on the international circuit. "It can," Imelda May notes wryly, "get a little repetitive."
A few weeks ago, May and her band were appearing at one such event in Canada. Craving escape from the ennui of her backstage confines, she went for a pre-show roam and spied, through a hole in the high perimeter wall, a tranquil lake. The fact that this lake was clearly off limits mattered little to her. She scaled the wall, jumped and landed awkwardly. "I heard a snap," she recounts now. "My tendon snapping clean away from the bone, so the doctor told me later. You would not believe the pain."
Somehow, she made it back over the wall and, now in considerable agony, into the backstage area, where her band berated her, a member of the St John Ambulance team was summoned, and oxygen was administered. Then, because May has always honoured the dictum that the show must go on, the show went on. "I did most of it hopping on one foot," she says. "And the moment the last song was over, I was helped into an ambulance and rushed to hospital. It was all very dramatic."
Appropriately so, perhaps, for it capped a summer full of high drama for the 37-year-old 1950s throwback, one of the year's more unlikely success stories. May's second album, Mayhem, which is full of lip-curling rockabilly, Eddie Cochrane by way of Wanda Jackson, has now spent almost a year on the charts and sold upwards of 200,000 copies. No one anticipated that she would become the sixth-highest-selling UK artist this year, and the past 12 months have been peppered with all manner of previously unthinkable highs: a mild snub to the Queen; an audience with Barack Obama; and the unrivalled pleasure of having Lou Reed sneer at her in a contemptuous manner.
But all she can focus on right now is the ankle. "It hurts," she says. "Like, a lot."
It is a Friday afternoon at the end of August and, because May is due to play at Hampton Court Palace tonight, an open-air gig exposed to the elements, it is of course pouring with rain, with a side-order of thunder and lightning. She has arranged to meet me in a café five minutes from the site, but a call comes after half-an-hour to say she is running late, in a taxi stuck in traffic eight miles away. "I'll be with you in 15 minutes," she says. An hour passes, and still no sign. Her driver, it transpires, got lost, got fed up, and dropped her off in the wrong place entirely. Her mobile phone died, and she had little idea where to find the café.
When she finally does appear, in a pair of Converse trainers that have not endured the weather conditions well, she is furious and full of apology. "I need cake," she says, sitting down, folding up her red polka-dot umbrella and trying desperately to calm herself. That she has emerged from the storm looking utterly glamorous – quiff indomitable, lipstick red enough to attract bulls – is no mean feat. But then May, a 1950s girl at heart, never goes anywhere knowingly underdressed.
"I don't do grey," she notes. "I like my colour, my style." And both are quintessentially vintage. "It is, and what's wrong with that? I'm sorry, but Juicy Couture tracksuits and Ugg boots don't move me in any way, shape or form. I refuse to wear them. Modern fashion doesn't appeal to me; the 1950s were better in every way, don't you think?"
The small Camden Town flat she lived in until recently with her musician husband Darrel Higham was, she says, "pure retro, beautiful. And we've got the best 1950s jukebox ever. It still works. Tell me, will your hi-fi system still work in 60 years' time? I doubt it."
Like the woman herself, Mayhem is an infectious album, a minxish brew of rockabilly, jazz and pop delivered with a salty, irrepressible attitude. Released last October, it slowly became a word-of-mouth hit, then a radio smash. It spent several months inside the top 10, and is about to return there this month, repackaged as More Mayhem and featuring new tracks. Its success represents a major vindication for the singer, and her mile-wide stubborn streak.
"Everybody told me that if I insisted on doing rockabilly music, I'd never have a chance of selling any records," she says. "In fact, I lost count of how many people told me to ditch it all together, in favour, I guess, of sounding like everybody else." Negotiations with her record company became increasingly heated. "It got to the stage that whenever I walked into their offices, I'd be taking off my jacket, rolling up my sleeves and saying, 'OK, let battle commence.' I'm sure they dreaded meetings with me, because I wouldn't budge. But then, who knows which direction my music should go in better than me? I'll tell you: no one."
She did at least have some reason for such bullishness. In 2007, her debut album, Love Tattoo, which was also full of ostensibly outmoded 1950s rhythms, topped the Irish charts. All well and good, her record company countered, but one doesn't need to shift very many records to top the Irish charts. For Mayhem, they were hoping for serious sales, and serious sales, they remained convinced, required crossover appeal. And the only way to achieve that was to dilute her very essence.
She bristles. "If you ask me, rockabilly has had a raw deal for far too long. People never shunned the blues or jazz the way they do rockabilly. But it's the original punk-rock, and it changed the way people looked at music for ever."
The Beatles, she continues, used to say that they would never have picked up their guitars if it hadn't been for rockabilly. Of course, Shakin' Stevens may well have claimed similar. "I'm not being nostalgic about it; I'm too young to be nostalgic. For me, my music is not just rockabilly, it's pop, and it's contemporary. It sounds good today. And I'm obviously not the only one who thinks so because, look, my record keeps selling, doesn't it?"
Born Imelda Mary Clabby in Dublin in 1974, she was the youngest of five children; her father was a painter and decorator, her mother a seamstress, and everyone in her family was musical. "But then all Irish families are," she points out. "Any excuse for a singsong." One older sister sang Christian folk songs; an older brother played in a traditional band. May herself was appearing on stage regularly from the age of 16, and by 22 had moved to London.
"Darrel had already moved over, and encouraged me to follow, promising me I'd like it," she says. "I was in love with him, so I agreed. The homesickness was something fierce, but I ended up staying."
They settled in Camden Town, married, and quickly became regular faces on a buoyant, if underground, scene. Over the following decade, she sang wherever and with k whomever she could: in rockabilly bands, country-swing bands, blues bands. She lent her voice to advertising jingles, and, once, a small independent film in which the lead actress was required to belt out a song. Meantime, she held down countless day jobs, as a waitress, in launderettes, and nursing homes. "I loved my life, but it was hard," she admits. "Me and Darrel were both working jobs and playing gigs wherever we could. It was good, but the penny jar was often low, and it was tough to make ends meet. It gets you down after a while."
In 2006, she decided to stop singing in other people's bands in favour of going it alone. "I could feel something rumbling inside of me, you know? It was time." She recorded Love Tattoo on the very smallest of budgets, and it was later picked up by a label, Decca, which was likely as surprised as she was when it reached number one in Ireland. She and Higham, by now part of her band, spent the next few years touring with Jools Holland, Jamie Cullum and even Meatloaf, so by the time Mayhem was released, May – now closer to 40 than she was 30 – was one of the few tangible "new" female singer-songwriters who could not be filed quite so easily alongside the raft of Winehouses and Adeles.
"I'm glad I'm a bit older," she says. "I think you appreciate it more if you've waited longer for it, you know? It'd be terrible having a big hit at 21, then realising that for the rest of your life you had to try to live up to it."
For the past few months, the rewards of her success have become increasingly apparent. Earlier this year, she found herself in a recording studio at the behest of legendary music producer Tony Visconti, who had been so taken with one of Mayhem's tracks, a gentle, Pogues-ish balled called "Kentish Town Waltz", that he wanted to record his own version of it as a duet between May and Lou Reed. "Meself and Tony hit it off immediately, a lovely, lovely bloke," she says. And what of Reed? Her smile comes hesitantly. "Yes, we got on as well... eventually."
When the great man first arrived at the studio, May quickly introduced herself. "I told him how glad I was that he was able to come down." Reed, a famous curmudgeon, looked down his nose at her, and mumbled back, "I'm only here for Tony." It wasn't until he realised she was the song's author that he deigned to replace condescension with something approaching respect. "And you know what? He sang it lovely."
Then, earlier this summer, May was requested to sing for the Queen during the monarch's state visit to Ireland. "But we were busy," she says. "We'd already committed to doing a gig for Sunderland FC, and Darrel is a massive Sunderland fan, so we weren't about to back out of that."
No matter, for a week later another invitation arrived. "We were asked back to Dublin to play for Obama, and that was great, surreal. We did our bit alongside everybody else, and then we all lined up to meet him afterwards: us, Daniel Day Lewis, Brendan Gleeson, Gabriel Byrne, even Jedward. And then your man himself comes in, Barack Obama, and he says hello, but he's quickly off, busy working the room. His wife, though, she hung around to chat. Lovely woman."
Before they departed, the assembled guests were presented with parting gifts. "Guess what it was?" she squeals. "Actually, don't, because you never will. M&Ms! Presidential M&Ms, stamped and sealed." And has she eaten them? "God, no! Kept them as a souvenir, haven't I? I ate Brendan Gleeson's instead..."
Perhaps in pursuit of re-engaging with real life, May and her husband recently invested in a new house. If anything has the ability to bring someone back down to earth, it's dealing with estate agents. At the beginning of September, they left their Camden flat in favour of a house in Hampshire, with its own studio attached. It is, she acknowledges, the perfect place for starting a family.
"Sure, kids would be great, but we're just trying to keep up with everything else at the moment, and that's difficult enough," she says. "I mean, things are going great here, and they're taking off in America as well, in Australia, in France even. France! Then we've got the next album to consider, and, well, my head is still spinning with it all. I barely know what day it is."
So I remind her. It's Friday. She checks the time, and realises that she is required now at the venue for soundcheck. As we leave the café, she makes small talk, and asks what I have planned for the rest of the evening. To come and see you play at Hampton Court, I tell her.
She surveys the driving rain, and laughs out loud. "You crazy fool," she says.
Imelda May's latest single, 'Roadrunner', and album, 'More Mayhem', are both out tomorrow. May embarks on a tour of the UK this November ( imeldamay.com)