By Christmas 2004, Jamie Cullum finally had a chance to catch his breath and get back to basics. He went home after months of touring, sat in front of his piano and began again, itching to create something new and process the previous two years of life, love and music in the only way he knew how.

"I was so ready for it," he remembers now. "The only way you get the energy to tour the world and do all the hard work is to love the music you make. I'd had two mad years but I was back at the place I remembered the best, which was just really wanting to do music. I'd done so many crazy things and had such a laugh that I can't imagine what my life would be like without the last two years though. That time changed my whole life, whatever happens next."

Jamie never even dared dream all this could be possible. Born in Essex and raised in Wiltshire, he was obsessed with all types of music from an early age but discovered jazz as a teenager, entranced from the moment he heard Miles Davis. By the time he went to university to study English, Jamie was working as singer-pianist in pubs, hotels, cruise ships and anywhere else that would have him.

"I had a gig the night before my finals," he says. "I missed my graduation to go on tour and then go on a cruise ship so music was all I was doing even then." In an attempt to get even more gigs, Jamie took out a student loan and recorded his first album. "I didn't dream of being a pop star or anything. I never thought I had the talent or the confidence or the ability to do this so it came up and surprised me. I mean, I made albums but I wasn't even selling them to record companies, I was just selling them at gigs and I didn't really think much more about it."

Word spread, though. Jamie moved to London and specialist jazz label Candid released his second album, 'Pointless Nostalgic', to a flurry of interest in jazz circles. Jamie, of course, continued gigging, by then a regular fixture at wedding receptions and Soho Pizza Express. Until Universal Classics and Jazz came to see what all the fuss was about, finally signing a 1 million record deal with Jamie in April 2003.

Even then, no one could have predicted 'Twentysomething', Jamie's first major label album released in October 2003. Tearing down the barriers between pop and jazz, it juxtaposed unique arrangements of jazz standards with a handful of his own original compositions and startling piano-led versions of songs by Jimi Hendrix and Jeff Buckley. It was an album by someone who loves music in all its forms and wanted to show everyone else what could be possible too. Within months, it had sold an incredible 2.5 million copies, making 'Twentysomething' the fastest selling jazz album in UK history and Jamie himself the biggest selling UK jazz artist ever.

"It was all a total surprise," he says now. "I never expected it at all but also I never really desired it in quite the way I think you're supposed to. I was so obsessed with the music part of it, I kind of forgot about the other things it might lead to."

Initially, it led to America. Jamie played a three week residency at prestigious jazz venue, The Oak Room at The Algonquin hotel in New York before touring the rest of the country for six weeks, where his frenetic, piano-hammering live show drew rave reviews .

"We did the full tour bus thing and I loved it," he says. "We played colleges, and little venues and rock clubs from Nashville up to Canada and it felt like living the dream. It was great." On this side of the Atlantic, Jamie headlined three sell out tours, was the subject of a South Bank Show and played a much-longed for slot at the Glastonbury Festival. "That was amazing. It was probably my favourite gig ever. I've got it all on video tape, looking a bit pissed while I play. There was nothing elegant about it - I even poured beer on myself at the end of the show - but it was great. Not just the gig either, I was there for the whole weekend in my tent. I loved it."

It was exactly the audience Jamie had hoped would sit up and take notice, even if they had never listened to jazz before. "I was surprised the way people embraced it but I always tried to present it and produce it in a way that would make them able to embrace it," he explains. "It's not unforgiving. It's adventurous in the way that it blends things but not necessarily in the discordance and the length that sometimes hardcore jazz can be. The way I like to approach music is to mix things round and, fortunately, I like to mix it with things that people find a bit more familiar. I love pop music so I mix jazz and pop music. Not because I want to make it accessible but because it's music that I enjoy. I guess I've just got an angle on it that people find a bit more interesting."

Of course, people were equally interested in the man behind the music, as the press noted his boy-band looks and on-stage charisma. Jamie remains bemused, but unaffected, by it all. "I do get recognised occasionally but it doesn't affect me in any way at all. I still eat, drink and shit in the same place and quite happily too! I'm just not that kind of person. As much as you'll see a person bounding around on stage and performing and you assume that they love the attention and that's all they want, I've never really craved that. It's just a by product of enjoying making music really."

One of the better consequences, though, was the chance for Jamie to meet his idols. From jazz heroes like Dave Brubeck ("He gave me a big hug") to Thom Yorke ("There's not much to tell but I shook his hand!"), it has been a year even Jamie can't get his head round. One particular highlight was meeting uber-producer, Pharrell Williams, at The Brits. "He was always someone that I wanted to meet but I never thought I would get to know him as well as I did and spend as much time with him as I have," Jamie says. "We've worked together, we've hung out. We've socialised and partied."

Jamie's stunning new album, 'Catching Tales', is certainly the result of a remarkable period in the 25 year old's life. Bursting with all the experiences and new music he has encountered on his travels, it took less than four months to write two album's worth of new material, interspersed only with lengthy pub visits as Jamie enjoyed life back at home with his friends and family. It is a breathtakingly accomplished record, more confident in both its experimentation and its intimacy. "It's a better representation of what I am and what I want to be as a musician," Jamie says. "I wanted the music to do more of the talking this time rather than having to explain it. There's a much more progressive look at the way this jazz/pop thing might be able to move forward. I think that I've worked out a way to express myself in this music better too. When I was growing up, I used to do that by playing soppy acoustic guitar songs and now I've worked out how to integrate that better. "At first I didn't think certain songs had a place in what I was doing with this jazz music but I've realised that everything does and it reaffirms my belief that jazz is the greatest platform to do whatever you want. People ask why I play jazz and it's because you can take it to so many different places. You can embrace dance music, rock, pop music, classical, funk, everything.. And I touch on all those things in this record."

Alongside a beautiful cover of Doves 'Catch The Sun' - "they're one of my favourite British bands" - Jamie couples his trademark takes on jazz standards with several self-penned tracks. "I wrote more this time because I had the time and I had the audience and I wanted to," he shrugs. "I also play standards, but when I made 'Twentysomething, not a lot of people were doing that and I think it's become a little bit more popular in the last two years so it immediately has less of an interest to me. I can't really explain why. It wasn't really a reaction to that, I just had loads of ideas and loads of good songs floating around and I fancied doing it. I put as much of myself into the arrangement of a song as I do into the writing of one though. I just had this burning desire this time to want to write but I would also think I failed if I didn't get just as much of myself through an arrangement of someone else's song."

This time around, he also experimented with collaborations. He worked on one track, 'Get Your Way', with renowned hip-hop DJ and Gorillaz member, Dan The Automator while Ben, Jamie's brother, plays the electric bass on most tracks and, most importantly, provided a much needed voice of reason during recording. "He's the best sounding board there is," Jamie insists. "The way it worked it was I would get up every morning and go to my little studio computer and sit up there in whatever I'd worn to bed and stay there until the afternoon. Then he'd come over in the afternoon, tell me to get changed and make a cup of tea and he'd lie on the floor and listen to what I'd done and tell me what he thought very candidly. This record wouldn't exist without him."

In addition, 'Catching Tales' features singer-songwriter Ed Harcourt, a collaborator on one of Jamie's own favourite album tracks, the sublime 'Back To The Ground'. "It's a classic touring song about when you get home and you readjust to life," Jamie remembers. "We literally caned a bottle of wine and jammed this blues song. He got on the guitar, I got on the Wurlitzer and we wrote the song within an hour. He was so inspirational, his impact is far more than just that one song and I definitely want to continue to work with him."

It fits perfectly on an album where usual musical constraints just don't apply and the possibilities of jazz, dance, hip hop and pop are challenged and attacked with fresh ears. Propelled by Jamie's sheer enthusiasm at starting all over again, 'Chasing Tales' marks the end of two mad years but the beginning of yet another chapter in Jamie Cullum's extraordinary life. "It's a big leap and a big evolution in a lot of ways," he reflects. "I've grown a lot and I think there's a link to the past as well as a new side of me on there too. It's a mixture of all those things and it's a better sum of what I am. I'm not thinking about numbers or selling more than the last one, I just want the opportunity to play this record for people. I'm so proud of it, that's all I need now."