* Off-Broadway--The musical "Little Shop of Horrors" will open tonight at 8 at the Madrid Theatre in Canoga Park. Based on the classic low-budget film made in 1960 by Roger Corman, the musical first opened off-Broadway in 1982 with a score by Howard Ashman and Alan Menken. A film version of the musical dark comedy, starring Rick Moranis, Ellen Greene and Steve Martin and featuring the voice of Levi Stubbs as Audrey II, was released in 1986. The theater is at 21622 Sherman Way. Regular schedule: Friday-Saturday, 8 p.m., and a matinee Jan. 29, 2 p.m. $16-$21. (818) 340-0221.
* King-Like--El Vez and the Memphis Mariachis, the Mexican incarnation of Elvis Presley, will perform Saturday at Palmdale Playhouse. El Vez, whose real name is Robert Lopez, puts on a show that has been described as half-tribute, half-parody. With his Elvettes--Priscillita and Lisa Marie--he performs in a variety of musical styles, with social commentary and humor mixed in. Show time: 8 p.m. The playhouse is at 38334 10th St. E., Palmdale. $8-$10. (661) 267-2787.