A daylong rock festival Saturday brings to Irvine the Allman Brothers Band, Blues Traveler, Big Head Todd and the Monsters and Sheryl Crow as part of the 32-city H.O.R.D.E. (for Horizons of Rock Developing Everywhere) tour. A midway-style concourse will include attractions such as a virtual-reality "LSD flight simulator," Jimi Hendrix memorabilia and a mechanical bucking bull ride. At the Irvine Meadows Amphitheatre beginning at 12:30 p.m. Tickets are $22.50 and $30. Call (714) 855-6111 or (714) 740-2000 (TicketMaster).