LONDON • His chiselled features have fronted a campaign for the British men's brand Dunhill, smouldered in advertisements for Giorgio Armani and Dior fragrances, and graced the pages of L'Uomo Vogue.
Fashion insiders were left breathless in January by his energetic catwalk performance at the Giambattista Valli show in Paris.
But this fashion It boy is neither a model nor an actor, neither a playboy nor a prince.
Charlie Siem is one of the rising stars in classical music. Born in Britain and educated at Eton College and Cambridge University, he is a violin virtuoso who has played with some of the world's top orchestras, including the Royal Philharmonic.
The 30-year-old, who began playing the violin at three, regularly writes his own musical compositions and has collaborated onstage with a host of pop and rock stars, including Lady Gaga and The Who.
As Siem climbed into the back of a taxi on a misty afternoon in London last month, he was pragmatic about the exposure fashion had given his career. "It's been a way of finding a whole new audience for my music," he said outside his parents' house on the fringes of Hyde Park, where he stays whenever he is in London.
Wrapped in a cashmere sweater, instrument at his feet, he was on his way to collect a suit from his tailors in Mayfair before a concert later that evening.
"My first steps into fashion were five years ago, which was just when menswear brands started having an interest in using real people as models. Having artists, musicians and personalities in campaigns is relatively mainstream now. But back then, I was part of an early wave."
He has made many friends in the fashion world. But he added that they had also given him insight into the rather unpredictable, chaotic nature of the industry, one very different from the rigours of classical music.
"Everything I've ever been booked to do has been so last minute: 24 hours' notice, sometimes less," Siem said. "It is a bit odd, given how they are often spending millions of dollars on their marketing. Shouldn't they be thinking about it all a little bit more? I am amazed at how it all always seems to come together."
With a relentless travel schedule that has him on the road more than 300 days a year, performing in countries such as China, Mexico and the United States, it is hardly surprising that when it comes to what he wears onstage, he chooses decisively to think less.
"It's easier to wear the same thing, isn't it?" he said. "A uniform of sorts. I needed something specifically engineered for all the movement that takes place during a performance. Trying to wear traditional suiting is virtually impossible. So I decided to design something myself."
The car slowed outside the location of the Mayfair tailors who assisted him in the creation of said suit: dark navy trousers and a stand collar jacket that closes on both shoulders, removing the need for a shirt and tie.
Smaller than its peers on nearby Savile Row, Meyer & Mortimer is nevertheless renowned for creating military and ceremonial attire since the 1790s.
"Unfortunately, there is a bit of a design fault with the concert suit," Siem said. "There is this double layering of material now and the high neck means in foreign countries and under bright lights, it becomes unbearably hot. I become like Niagara Falls, with great streams of sweat pouring down my face."