Joss Stone has reportedly been snubbed by former Queen guitarist Brian May - after the musician pulled out of a duet with the young star to concentrate on his studies. The pair were due to perform together at the Concert For Diana on Sunday (01Jul07), as a tribute to the late British royal Diana, Princess of Wales. But May has cancelled the duet to concentrate on coursework for his astronomy PhD qualification. However, Phil Symes, May's spokesperson, denied Stone and the rocker were due to perform together at the Wembley Stadium gig in London. He says, "He was never confirmed although they were in discussions about it. "Brian is up to his ears trying to complete his PhD thesis so he couldn't do it."