British actor and musician David Kaff, best known for portraying keyboardist Viv Savage in Rob Reiner’s 1984 mockumentary “This Is Spinal Tap,” has died at age 79. His current band, Mutual of Alameda’s Wild Kingdom, said Kaff “passed away peacefully in his sleep” on July 11; no cause of death was given. Born David Kaffinetti in 1946, Kaff co-founded the progressive-rock outfit Rare Bird, whose 1969 single “Sympathy” reached No. 27 on the UK chart and sold around one million copies worldwide. He also recorded with Chuck Berry on the guitarist’s 1972 album “The London Chuck Berry Sessions.” Kaff’s turn as Viv Savage delivered several of the film’s most quoted lines—including the closing “Have a good time, all the time”—and led to live appearances with the fictional band during its 1984 promotional tour, notably on Saturday Night Live. He did not return for subsequent Spinal Tap albums and is not listed among the cast of “Spinal Tap II: The End Continues,” due in US cinemas on Sept. 12.