Isaac Waddington, the 15-year old BGT act who entranced the judges and made the audience cry

When he told the audience his age, there was an eruption of 'awwww' to which he responded jokily, "It's not that cute."

And Isaac's performance wasn't cute, but surprisingly mature, bluesy and genuinely moving. As he sang and played the piano to the 1977 classic, his little brother Jack was in tears, as was his dad.

Isaac has been singing all his life and is a treble in the Scottish Chamber Orchestra. In 2012 he won the BBC Young Chorister of the Year, leading to an appearance on the BBC's Songs of Praise.

Isaac said he just wanted to make his family proud with his BGT act, and it's clear he achieved his aim with what judge Alesha Dixon said was a "flawless" performance.

In fact, his musical talent bowled over all the judges and he got four 'Yes' votes. For part of the performance, David and Alesha were both listening so intently that they had their eyes closed. Alesha told Isaac she had "got completely lost in the song" and Simon said he felt they'd found somebody "really, truly special."

David was so keen, in fact, that he asked Simon if he could have Isaac on his (non-existent) record label, even just for a year or two, to which Simon gave an emphatic "no". Unsurprisingly, Simon wants the amazing singer all to himself.

Britain's Got Talent continues next Saturday at 8:00pm on ITV