Shulamit Ran, the Israeli-born, Chicago-based, Pulitzer-winning composer, is possessed of extraordinary candor, leavened by her warm wit. When asked what is being celebrated in a “65th anniversary concert” of her music on Sept. 22, performed by the Da Capo Chamber Players, she readily admits complete bafflement.

“I have no idea what this is the 65th anniversary of,” she says without hesitation. “Da Capo has been thinking about this; they’re doing a concert of my music and I’m thrilled. They’ve been wonderful exponents of my music, so I say, ‘Thank you.’”

Indeed, Da Capo have been longtime supporters of Ran, with the collective commissioning works from her and individual members doing the same independently. When you speak to Ran or to a member of Da Capo, the mutual admiration and obvious affection fly fast and giddily.

“She’s one of our favorite composers to interact with,” Patricia Spencer, the group’s flutist, says. “She’s a musician’s composer. She understands what goes into making something happen [instrumentally] and can be flexible [if it means] a better result. She understands the instruments and she always makes decisions based on musical considerations, which is in itself fabulous.”

The Sept. 22 program will feature five pieces spanning a significant chunk of Ran’s career, from “Hyperbolae,” a solo piano piece from 1977, to two 2011 compositions, “A Due” for violin and cello, and “Moon Songs” for soprano, flute, cello and piano. The 1990 composition “Mirage” was written for Da Capo, and the 1978 “For an Actor: Monologue for Solo Clarinet” was written originally for then-member Laura Flax.

Does she see herself as an Israeli composer, an American composer, a Jewish composer? The identity question troubles her.

“I’m not sure that I’m any closer to answering it than I ever was,” she confesses. “I’m a dual citizen, but Israel is in the innermost core of my thinking and being. I go back, I’ve taken my children since they were born. It’s a constant part of my life and my existence. As for Jewish music or Israeli music — I am who I am so the music I write is by definition — you could say whatever you want to say, because it’s written by a person who identifies who she is.”

She directs the interviewer to her piece “Moon Songs” for an explanation.

“It’s a big work that uses a wide range of poetic sources in English and Hebrew,” she says. “There’s poetry by Haim Gouri, one of Israel’s greatest poets, the medieval poetry of Ibn Gabirol, the work of Almog Behar, a younger Israeli poet and quite a bit of English too. … There are a lot of sources in my music that I’m interested in, but I come back again and again to that well from which I come myself.”

The Da Capo Chamber Players will perform an evening of Shulamit Ran’s music Monday, Sept. 22, 8 p.m. at Merkin Concert Hall (129 W. 67th St.). On Nov. 7, Ran’s “Glitter, Doom, Shards, Memory, Quartet No. 3 for Strings” will be given its New York premiere by the Pacifica Quartet at Alice Tully Hall (Lincoln Center), 7:30 p.m.