Hunter Hayes got a thumbs-up from Sir Paul McCartney for his Grammy Awards appearance.

The rising American musician performed his track 'Invisible' at the awards show last Sunday (26.01.14) and although he was too star-struck to approach the legendary singer/songwriter, the former Beatles star personally came over to give him some words of encouragement.

Hunter said: ''As I'm standing there, Sir Paul walks through, and he looked at me and I looked at him and it was one of those, 'Man I really wanna talk to him but I do not have the guts.'

''[But] he stops in his tracks and he points at me and goes, 'Hey!' And he came to me and said great things about the performance and he said things about my voice that I really don't honestly believe. He had nothing but good things to say!''

Hunter says his single - which is about outcasts, rebels and people who are perceived as ''different'' to normal society - is based on his own high school experiences.

He added to radio station KNCI 105.1: ''I can, if nothing else, speak for the 'me' who was in high school as a music geek and a total nerd...and this song is my way of saying there is absolutely nothing wrong with that.''