Since his first public piano recital in 2008, James Rhodes hasn’t stopped. He has performed all over the world; released five albums; written for The Telegraph and The Guardian; written his memoir, filmed documentaries for BBC Four, Sky Arts 2 and Channel 4 and is about to feature in another series Don’t Stop the Music for Channel 4; and is getting married at the end of the month, just before he comes to Watford to play live.

“I did an interview for The Guardian this morning, then some filming and a photo shoot for the series, then rushed back to the piano to practise for the new tour, and now I’m speaking to you,“ says the 39-year-old, in the rapid-fire delivery that characterises most of his speech and mirrors his hectic lifestyle.

“It’s actually good to keep busy – if I’m not I think too much and that’s when I get into trouble.“

It’s not an overstatement to say that music has saved James’ life.

“It’s the only thing that’s never, ever let me down. People are human, they let you down, jobs let you down, you get sick, your body lets you down and your mind – but music is the one thing that’s always there, no matter what, and always makes me feel immortal, I guess. Which is quite nice, isn’t it?“

James, who lives in Maida Vale, has spoken openly about the sexual abuse he suffered as a young child by his gym teacher at a public school in north London and his subsequent emotional and physical problems – the abuse damaged his spine, requiring him to have surgery aged 13, and he suffered a breakdown as an adult and was institutionalised for several months, diagnosed with “so many things, there’s this long list of things I’ve got, it’s inexact“, but including depression and schizophrenia.

“If you’re lucky enough to have even a small voice in the public eye, it would be totally wrong to hide it away,“ says James, “to keep things secret when that’s what so many are told to do when they go through it.

“It’s certainly not something that I dwell on and it’s not who I am, but it’s a part of me, just as playing the piano is or being a Pisces is.

“Yeah, I’m open about it and from some of the messages I’ve got it’s been quite helpful to people, it’s nice to know that we’re not alone.“

James discovered from the age of seven that he could escape into classical music after “stealing” a cassette from his father’s music collection that contained Beethoven’s Emperor Concerto and the Bach Busoni Chaconne.

“I was a weird kid,“ he laughs. “I don’t understand why, but somehow the stars all aligned and there seemed to be this thunderbolt that went straight inside my heart, and ever since then...

“Thank God it was music and not Jesus, I would’ve been insufferable! But it was music and it did things to me that nothing has ever been able to emulate, no drug, no girl, no amount of money, none of that. I just knew that was what I wanted to do.“

But it took James rather a long while to get there.

He didn’t start learning the piano seriously until he moved to Harrow School at the age of 13 in the late 1980s, where he came under the tutelage of Colin Stone.

“He was amazing. He was the only person I’ve ever come across who met my crazy halfway. He totally got that I was insanely enthusiastic. I could never sit quietly for an hour and do scales, I just wanted to play and, like a kindly uncle, he just smiled and nodded and let me do my stuff.

“I still go and play for him and get advice. He’s my oldest friend now.“

And then in 1993, aged 18, James stopped playing the piano entirely, partly due to mental health issues and partly because his parents “thought it would be better to get a more rounded education, whatever the f*** that means“.

He passed up a music scholarship to the Guildhall School of Music and Drama and went to Edinburgh University instead, dropped out after a year, “ended up in several psych wards“, then went to University College London to “ironically“ study psychology.

He then took a well-paid financial job in the City to try and make some money and scratch the itch left by not playing the piano.

“And by then I was sick and tired of being sick and tired, so I quit and threw myself into the piano.

“I was 28 and hadn’t played anything for ten years. I had to go back to it as a slightly bashful adult and unlearn all the bad habits I’d picked up.“

James met Franco Panozzo, the agent of the Russian concert virtuoso Grigori Sokolov, who arranged for him to be tutored by the renowned piano teacher Edoardo Strabbioli in Verona in Italy.

He suffered further mental health issues, which delayed his career even further, but in 2008 met the man who would become his manager, Denis Blais, who helped him realise his dream of being a professional pianist.

James has detailed his journey in his memoir Instrumental, which pays tribute to the therapeutic power of music as well as giving a fascinating insight into the lives of some of his favourite composers, who James describes as the “original rock stars”.

“They didn’t throw televisions out of hotel windows, they threw themselves out. They were bat-s**t crazy, but wrote this extraordinary, overwhelmingly immortal music.

“I think everyone’s a bit bat-s**t,“ James continues, his pace still not flagging. “I haven’t met anyone who isn’t, but I suppose it’s how you channel it. I’ve never bought into the idea of the tortured artist, that whole link between depression and creativity – I think you do that stuff despite being depressed or hating yourself or wanting to die, not because of it.

“I think if you’re lucky enough to find an outlet for all that crazy, whether it’s art or writing or music or whatever, then you’re in with a chance of doing something really brilliant. The important thing is to find it and then just relentlessly pursue it.“