David Crosby, Stephen Stills and Graham Nash, the supergroup that made its concert debut 45 years ago this month at Woodstock, brought much nostalgia to the Saenger Theatre on Saturday night. But showing they’re still a creative force, they blended new songs amid the classics.

The concert — featuring the trio with a full band, plus Nash and Crosby as a duo as well as all three members in solo performances — unreeled as a variety show and a career-spanning retrospective.

Nash, 72, often stood center stage. He acted as low-key master of ceremonies and cheerleader for Crosby, 73, Stills, 69, and the band members.

“How are you this evening, New Orleans?” the British-born Nash asked on a night of steambath humidity. “Warm enough for you?”

From the evening’s opening song, it was obvious that Crosby, Stills & Nash’s one-of-a-kind vocal blend remains intact. Nash and Crosby have stronger voices than their colleague, but Stills’ guitar skills were undiminished, and his singing improved as the show went on.

The group opened with four classics: the Stills-composed, multisectioned “Carry On”; Nash’s light and happy “Marrakesh Express”; the dark and passionate, Crosby-penned “Long Time Gone”; and another Stills composition and dramatic CSN highwater mark, “Southern Cross.”

Those enchanting CSN harmonies arose again in Nash’s gently regretful song of farewell, “Just a Song Before I Go.”

Crosby, looking wizardly with his cascading white hair and massive white mustache, subsequently joked: “So that’s it for the hits. From now on, totally unrecognizable stuff. I’m lying. … We saved a couple for later.”

Crosby performed his not-so-obscure, lovely ballad “Delta,” from the 1982 CSN album “Daylight Again.” Nash, who has worked with Crosby in a duo format minus Stills, joined in harmoniously.

“If you’ve seen us before, you know we have different jobs,” Crosby explained later. “Stills writes fantastic rock ’n’ roll. Well, he writes everything, and he writes fantastic. Nash writes these anthems that the world wants to sing. And I write the weird stuff.”

The variety continued when Stills took the spotlight for “Don’t Want Lies.” A terrific song he co-wrote and recorded with his friend from Shreveport, singer-guitarist Kenny Wayne Shepherd, it was among his strongest turns of the night.

There was more new material with “Back Home,” written in honor of Levon Helm, the late drummer and singer in The Band. “Back Home” segued into a few measures of The Band’s “The Weight,” solidifying its place among the evening’s special moments.

Nash sat in the spotlight at a keyboard for his meditative “Cathedral.” If he lost members of the audience during the trippy, ethereal song, he instantly retrieved them with his simple, touching ode to home, “Our House.”

Before Stills — whose military family lived many places, including Louisiana, during his childhood and youth — performed his solo acoustic rendition of Bob Dylan’s “Girl of the North Country,” he recalled singing that song for his first professional music job, 51 years ago at Cosimo Matassa’s recording studio on Gov. Nicholls Street in the French Quarter.

On another local note, Nash announced that the band’s keyboard player, James Raymond, is from New Orleans. Not true. Throughout the tour, Nash has been telling audiences that Raymond is from whatever city CSN happens to be in. In reality, Raymond is Crosby’s son and a California native.

CSN’s Saenger show began a few minutes after 8 p.m., broke for an intermission and resumed at 9:50 p.m. for another 70 minutes of music. New material aside, the concert featured enough classics to please the delighted audience. A few of Stills’ songs from his pre-CSN group, Buffalo Springfield, also went over big.

CSN’s encores brought the crowd up with “Love the One You’re With” then sent them physically back into the Canal Street heat, yet spiritually, you might say, back to the garden with the gentle, loving message of “Teach Your Children.”

“And most of all, we wish you peace,” Nash said.