CHICAGO – Allen Toussaint’s vast impact on music the last 50 years is sometimes underappreciated because much of his best work has come behind the scenes. And that’s just fine with the softspoken, 75-year-old New Orleans songwriter and producer, whose greatest songs – from “Working in the Coalmine” to “Southern Nights” – were often popularized by other artists.

Now he’s touring as a solo act. He’s comfortable with the idea now, but it was a leap for Toussaint when he began playing solo at Joe’s Pub in New York City after his home and studio in New Orleans were devastated by Hurricane Katrina in 2005. The producer has since moved back to New Orleans, but says his time in New York marked a turning point in his career.

“When I first started doing Joe’s Pub, every moment was reluctant,” he said. “It was tough for me. My comfort zone was the studio – I had that scene down, getting that environment and spirit right. But for them to announce you and it’s just you, and the people are right there, it’s a whole different world for me. The first few times, I didn’t know if I was giving people what they deserve. I actually missed the arranged and produced versions of my songs, and seeing the backing voices working together. But I’m glad I had another chance to do it, and another. And I began to enjoy it. I’m glad to say it’s getting better and I even have a good time sometimes.”

Toussaint’s modesty belies the brilliance of his solo performances. Accompanying himself on piano, where he develops counterpoint melodies and cross-currents of rhythm that suggest three people are sitting at the instrument instead of just one, Toussaint sings in a high, mellifluous voice that epitomizes New Orleans soul. Some of the best performances from his extended Joe’s Pub residency are preserved on a recent album, “Songbook” (Rounder), another landmark in a career full of them. In many ways, the solo shows take Toussaint back to his childhood, when he taught himself to play on an out-of-tune upright piano at home.

“The main thing was to mimic everything I heard on the radio,” he said. “I tried to play everything I heard – blues, R&B, gospel, even classical. I remember learning a Grieg piano concerto in the wrong key, because my piano was a bit flat. I flipped around the dial and heard hillbilly – Red Foley, Ernest Tubb – and boogie-woogie, gospel. Music baby-sat me through my childhood.”

His talent got him into studio sessions as a teenager, playing piano alongside another up-and-comer named Dr. John.

Toussaint went on to write, arrange or produce countless classics, including Lee Dorsey’s “Ya Ya,” Irma Thomas’ “It’s Raining,” Chris Kenner’s “I like it Like That” and “Fortune Teller,” which has been recorded by the Rolling Stones, the Who and Robert Plant-Alison Krauss on their Grammy-winning “Raising Sand” album.

His own recordings weren’t huge commercial hits but are revered by New Orleans music connoisseurs. Though reluctant to write from a particularly personal perspective, “Southern Nights” proved a rare exception and one of his most enduring songs. The title track of his 1975 album, it later became a massive hit for Glen Campbell, and Toussaint plays an extended version on “Songbook.”