Born Jonathan Mark Ansell on March 10, 1982, in Bognor Regis, Sussex, England, he began performing at age eight, when he joined the West Sussex Boys Choir, of which he remained a member until puberty. Before his voice broke, he sang treble; afterward, he was a high tenor. In time, he was awarded the opportunity to attend the prestigious Guildhall School of Music and Drama in London. There he befriended fellow students Mike Christie, Tom Lowe, and Ben Thapa, with whom he formed the pop-opera group G4 (Guildhall Four).

In 2004 G4 (in which Matthew Stiff had since replaced Lowe) competed on The X Factor, a televised talent show hosted by Simon Cowell on the ITV network, and won second place, losing to first-place winner Steve Brookstein. In turn, the group was offered a lucrative recording contract with Sony BMG and released its debut album, G4 (2005), which topped the U.K. albums chart and ultimately outsold the likewise chart-topping debut album of Brookstein, Heart & Soul (2005). Over the next two years, G4 toured the U.K. five times, selling out each tour; they released two additional albums, G4 and Friends (2005) and Act Three (2006), and released the DVD Live at the Royal Albert Hall (2005). In the wake of this success, G4 announced its breakup in April 2007, citing inner-group tension.

Ansell proceeded to sign a lucrative solo recording contract with Universal Music Group. His debut solo album, Tenor at the Movies (2008), a collection of film theme interpretations, topped the U.K. classical albums chart, making him the youngest tenor ever to do so. It peaked at number nine on the overall albums chart. ~ Jason Birchmeier