Before Ira Gershwin’s death in 1983, he made Feinstein his literary executor. Things didn’t end well. “I had a falling-out with Mrs. Gershwin after Ira’s death,” he says. “I signed a paper relinquishing all rights. I was strong-armed into signing something.”

By the mid 1980s, Feinstein was making a name for himself as a pianist. He accompanied Liza Minnelli on The Tonight Show Starring Johnny Carson in 1985, and the next year recorded a live cabaret performance at The Algonquin hotel in New York City. His first studio album, in 1987, was Pure Gershwin.

Feinstein has made dozens of recordings including tributes to golden-age composers Irving Berlin and Jule Styne, a gender-bending duets album with Broadway performer Cheyenne Jackson and two Sinatra discs.

In 2007, he founded the nonprofit Michael Feinstein Great American Songbook Initiative, based at the Center for the Performing Arts in Carmel, Ind., where he is artistic director.

Thousands of young people have applied to compete in the initiative’s annual Great American Songbook High School Vocal Academy & Competition, says the entertainer, who also runs a namesake cabaret in Manhattan.

“At 20, I was playing in piano bars. I expected having a life playing in piano bars. I didn’t think I had the talent to do anything else. I didn’t think I could make a living singing songs that were 50 years old,” says Feinstein, who married partner Terrence Flannery in 2008.

“There wasn’t a place for me. I was constantly told I couldn’t’ make a living singing old songs. “It’s amazing to me that this has evolved to this stage. It’s wonderful. I’m most grateful for it, but I never expected it.”