Time has been hard on the artists who gave the festival its identity for decades.

When conversations about how and why Jazz Fest has changed cropped up, writer John Swenson used to point to the passing of New Orleans’ greatest R&B generation. It’s a natural byproduct of time passing, but long-time mainstays Allen Toussaint, Eddie Bo, Ernie K-Doe, Snooks Eaglin, Earl King, Bo Dollis, and Art and Charles Neville have passed, among countless others.

They flew the flag for New Orleans R&B at its most eccentric and inspired, making music with clear, broad roots that nonetheless foregrounded personalities that were inseparable from their sound. For many music fans from around the world, they were talismans for the Crescent City and Jazz Fest, and while the music remains solid, the festival is just a little more conventional without them.

Only Irma Thomas, Germaine Bazzle, Big Chief Monk Boudreaux, Wanda Rouzan, Barbara Hawkins of The Dixie Cups, and Al “Carnival Time” Johnson from that generation are still alive and on the Jazz Fest schedule this year. The Dixie Cups, Rouzan, and Johnson are scheduled to perform as part of the New Orleans Classic Recordings Revue on Thursday, April 25 at 3 p.m. on the Shell Gentilly Stage, where they were scheduled to also pay tribute to Jean “Mr. Big Stuff” Knight, who passed away last November. Clarence “Frogman” Henry was slated to be part of that revue, but he’ll likely become part of its tribute since he died Sunday.

The 1982 movie Diner introduced a generation to Henry’s “Ain’t Got No Home,” and while it wasn’t his only song, it became his identity in much the same way “Carnival Time” is Al Johnson’s musical signature. Unfortunately, Henry had been in poor health with back problems for years, and died after complications from a recent back surgery.

After Irma Thomas (May 5, Festival Stage, 1:55 p.m.), Bazzle (May 3, WWOZ Jazz Tent, 1:30 p.m.) and Boudreaux and The Golden Eagles (April 28, Jazz & Heritage Stage, 4:25 p.m.), the last people flying the flag for an earlier generation of New Orleans’ funky R&B are The Dirty Dozen Brass Band (April 28, Festival Stage, 2:05 p.m.) and the remaining Meters: Zigaboo Modiste and the Funk Revue (April 26, Shell Gentilly Stage, 12:45 p.m.), The Uptown Ruler Cyril Neville (May 3, Congo Square Stage, 2:40 p.m.), Leo Nocentelli (May 4, Shell Gentilly Stage, 2:05 p.m.), and George Porter Jr. & Runnin’ Pardners (May 5, Festival Stage, 12:30 p.m.).

It goes without saying that we can’t take any of them for granted.