In the late ’50s, when he was two and a half, Dick Gallagher started picking out tunes on the piano. He’s been doing it ever since. So much so, he now estimates he’s at the keyboard accompanying someone approximately 150 evenings a year. When he’s on the job, his piano playing and his arranging are like the chisel-featured guy himself—elegant, subtle, tailored.

A couple dozen of the 150 gigs are leading lady Patti LuPone’s, whom he calls “a good pal.” The music man has a Rolodexful of them. They’re the people for whom he musical-directs, arranges, coaches, and/or composes songs. Included in the crowd trooping to his Chelsea digs for rehearsals are cabaret fixtures like dynamic and sassy Sally Mayes, dramatic and high-powered Karen Mason, oh-so-French Liliane Montevecchi, strong-piped and raucous Lina Koutrakos, big baritone Eric Michael Gillett, saucy Teri Lyn Paul (the next project is “The Love Songs of Elvis Presley”), creative Charles Busch, and Rock Albers, a comic who wears rabbit ears.

In the immediate future, the good-pal ranks are being swelled by chanteuse Marishka, who’s got a string of Judy’s Chelsea dates starting this week, and chanteur Parker Scott, due next week at Don’t Tell Mama. For the former, Gallagher is using two additional instrumentalists—a percussionist and an accordionist. He admits to not being thrilled with the charts part of the assignment. “There is hardly an arranger I know who likes writing charts—they’d rather stick forks in their eyes,” he says. Nevertheless, his output contains abundant beauties, as his arrangements of Stephen Sondheim, John Bucchino, and Randy Newman for LuPone’s Matters of the Heart CD attest. So do the tasty items for Mayes’s recent Boys and Girls Like You and Me CD.

Gallagher’s songwriting, which he does in what might jokingly be called his spare time, goes well, too. Over the past few years “Laughing Matters,” about the need for amusement in troubled times and written with Mark Waldrop for the musical revue When Pigs Fly, has become a cabaret staple. Gallagher says the team’s “Last One Picked” has become an evergreen at auditions—an odd, but notable distinction. Gallagher and Waldrop have also written two shows for TheaterWorks USA—Gold Rush and, more recently, a version of A Christmas Carol. Lina Koutrakos, who leaped from boîte to rock a few years back, is another collaborator to the tune of a few dozen ditties. For the rabbit-eared Albers, Gallagher has run up 90-second novelties about ribbable subjects like Martha Stewart, Donald Trump, and Janet Reno.

Perhaps what makes Gallagher so knowledgeable, and therefore sought after, is his interest in the history of arrangements. For instance, he knows plenty about Kay Thompson, who may be considered a relic now but who seminally shook up nightclub entertainment in the late ’40s. To draw from his expertise on this and other topics, how many telephone calls does Gallagher get during an average day? “I get a lot,” he says, with characteristic understatement.