This has been the winter of Rupert Holmes' content. He took the irresistibly catchy Piña Colada Song—named for a pineapple, coconut and rum drink designed for hot weather—and turned it into the first big hit of the decade. Its success got the 33-year-old Holmes off the Dole at last, and now his follow-up single Him has likewise cracked the Top 10.

Only a year ago Holmes was the best-known unknown in pop. His four albums prior to his current Partners in Crime amounted to "the most expensive demo tapes ever," he observes. "The only people buying them were Barry Manilow and Dionne Warwick." He's telling the truth about their interest in him. While his own singing career languished, Holmes kept afloat writing songs later recorded by Manilow, Warwick, Dolly Parton and Mac Davis, among others. But when Barbra Streisand called, Rupert blanched. "I was completely out of my depth. I thought it was somebody at the bowling alley playing a joke."

Recovering his poise, he had the keys to Barbra's Bel Air mansion six weeks later and briefly lived in her guest house while working with her. (Once he snuck up on her Funny Girl Oscar and faked an acceptance speech.) Rupert arranged and co-produced Barbra's 1975 Lazy Afternoon LP and wrote several songs for A Star Is Born. Then, tired of feeling like "Barbra's boy"—"All anybody wanted to talk about was Barbra"—he went back to singing and discovered piña coladas. "It's true I never met a drink I didn't like," he admits, "but this is not Julia Child set to music." (The lyric tells of a man who answers a lovelorn ad for someone who likes piña coladas—and finds it was placed by his girlfriend.) Besides, Holmes reveals, "My favorite drink is Jack Daniel's and soda."

Rupert was born in England to an American Gl father and a British mother ("It was just like Yanks") and grew up outside New York City. His dad, a music teacher, started him on clarinet at 8, though Holmes now jokes that "today's prodigies are tomorrow's psychotics." At 6 Rupert wrote his first song, with the already-anxious title of Nobody Loves Me. In school, he recalls, "I was skinny before Mick Jagger made it sexy, and I was into music when it wasn't cool to be into music. I thought my parents paid my friends to be my friends." In high school he formed a band, the Nomads, and by 23 had written a novelty single about cannibalism, Timothy, that crept into the Top 20.

After dropping out of the Manhattan School of Music, Holmes wound up in a studio control booth—"on the wrong side of the glass"—arranging for the Drifters and the Platters. Along the way, Holmes also scored everything from porno flicks to TV commercials. (Every time Dorothy Hamill skated for Short & Sassy, he collected "something like $48.")

Rupert's lyrics often deal with the unpredictability of male-female relationships. "I'm the stunt man of romance," he says. "I've been falling in love since I was 3." While living at the Continental Hyatt House in Hollywood, he claims, "I learned everything I know about sex in the elevator. The Rolling Stones had the entire floor above mine. If the groupies couldn't get to Mick, the guy in the room below was okay. I got the rejects."

He is far less flip about his on-again, off-again marriage of 12 years, his wife Liza, and their 4-year-old daughter Wendy. "I married very young [21], and we've gone through a lot of ups and downs," he says. "The best thing from that struggle is that she has found her own identity. I want her to have her own life." He seems reasonably satisfied with his, but adds, "I have some place to put the pain, but having hits doesn't make it all better. I still keep a psychiatrist and three bartenders working. I'm the Episcopalian Woody Allen."

Rupert's comic style includes satirical thrusts at rock stars "who blame their listlessness on grass" and drive "limos with Jacuzzis in the trunk." A "professional pedestrian," he doesn't drive at all, commuting by taxi to his Manhattan office from a three-bedroom New Jersey apartment he shares with his wife and daughter. In his spare time Holmes tends to his pet cat Sherlock, plays pinball in Times Square ("I'm into sleaze") and collects old radio tapes, 1939-40 World's Fair knickknacks and Art Deco glass.

Holmes will perform only his own music, explaining that his talents are limited: "Nobody ever said, 'I really want to hear Rupert sing that.' " He dreams of someday turning his songs into movies. "Some of the stories I want to tell just can't be squeezed into three and a half minutes," he explains, "and not all of them rhyme. I have this fear of going to my grave as the Piña Colada man. Sometimes," he continues, "I lean back, look into space and see my tombstone after I've died. There it is, with a big pineapple carved into it."