LIVE ACTION: Tickets go on sale Monday for the Firm's concerts May 22 at the Forum and May 23 at the Pacific Amphitheatre. . . . Tickets will be available Sunday for Judas Priest's May 11 Los Angeles Sports Arena date. . . . Simply Red will be at the Palace April 11. . . . The Cult returns to town with a Hollywood Palladium show April 26. . . . Rush will conclude its American tour with concerts May 25 and 26 at the Pacific Amphitheatre.