Scottish singer Susan Boyle is said to have left the 'America's Got Talent' show in Los Angeles in tears after a songwriter refused to give her permission to sing one of his hit songs.

Boyle, 49, had arrived at the show to perform the song "Perfect Day", but sources revealed that when producers sought permission from songwriter, Lou Reed, she was denied, TMZ.com reported.

Reed, who is the former lead singer for The Velvet Underground and famous for "Walk on the Wild Side", refused permission because he isn't a Boyle fan.

When Boyle found out, she dissolved into tears, as she was unprepared to change her tune for the show. (ANI)