Josh Groban goes back to what he knows best on his latest album 'Stages'; a collection of re-hashed mesmerising showtunes from all the best musicals, and on which he also got the chance to team up with three-time Grammy award winner Kelly Clarkson.

Josh Groban in LondonJosh Groban teams up with Kelly Clarkson in 'Stages' album

Groban is joined by Clarkson on track five 'All I Ask Of You'; a song famously sung by the characters Christine, Raoul and the Phantom in Andrew Lloyd Webber's 'The Phantom Of The Opera'. It has to be said, this new version is rather remarkable, with Clarkson's almost unrecognisable pipes rivalling those of even its most famous singer Sarah Brightman.

'Her voice is so wonderful and can do so many things', Groban admitted in an interview with Scott Shannon at WCBSFM. 'I've been a fan of her singing voice for so many years and I just had a hunch she could tackle this kind of song.' He confesses, however, that he was initially nervous about asking her given that she had a lot going on in her life and career at the time; from the birth of her first baby to her own album release 'Piece by Piece'. 'She loves this world too and was excited to do it and loved the challenge', he continued. 'She sent me an iPhone demo the first night she got the song.

Watch the full interview here:

Interestingly, it was that song that partly propelled his career; his vocal coach at the age of 17 Seth Riggs gave a tape of Groban singing the song to record producer David Foster, who then went on to work with him as he prepared to study at Carnegie Mellon University.

More: Josh Groban has also previously sang with Barbra Streisand

'These are songs that I grew up with in musical theatre', he explains. 'Some of my first experiences in music were from these shows and from these songs. I was signed while I was studying theatre. There was such a fork in the road but, seven albums later, to finally have a chance to get to these songs and to record them the way I want to was a thrill for me.'

More: Listen to Kelly Clarkson's tune 'Heartbeat Song'