Guest vocalists for the Beatles bonanza at the Hollywood Bowl on Aug. 10 and 11. Before Cheap Trick performs of "Sgt. Pepper's Lonely Hearts Club Band" in its entirety, the Hollywood Bowl Orchestra will trot out other Fab Four faves with Cheap Trick as the house band. With the orchestra, Ian Ball of Gomez will sing "Strawberry Fields Forever," Rob Laufer, who once played George in "Beatlemania" and participated in an earlier Beatles-George Martin tribute concert at the Bowl, will sing "Norwegian Wood"; and Joan Osborne will do "The Long And Winding Road." Aimee Mann will do "Blackbird." Orchestra will also perform "Magical Mystery Tour," "Eleanor Rigby" and "Golden Slumbers/Carry That Weight/The End." An Indian instrumental ensemble will perform George Harrison's "Within You Without you."