R+B star Usher has joined the line-up for tennis ace Andre Agassi's Grand Slam For Children concert tomorrow night (01OCT05).

The Yeah?! singer joins Celine Dion, Duran Duran, EARTH, WIND + FIRE, George Lopez, Glenn Frey, Mary J Blige, Robin Williams and a surprise guest at the 10th annual benefit concert.

The Grand Slam For Children concert fundraiser benefits the Andre Agassi Charitable Foundation, a non-profit organisation set up to assist at-risk youth in Agassi's hometown of Las Vegas.