A Tony Award-winner for “Hairspray,” and a seven-time Oscar nominee, Marc Shaiman has written about his nearly 50 years in show business in a new memoir, “Never Mind the Happy: Showbiz Stories From a Sore Winner.” Shaiman talks with Tracy Smith about collaborating with Billy Crystal on parody songs for the Oscars; composing scores for Rob Reiner’s films; and why he says, beginning as a piano prodigy at age 16, “there was no stopping me.”