On this, Allman Brothers guitarist Warren Haynes’ second trip to the Jazz Fest, he’ll be working when he’s playing.

Over the two-and-a-half days he’ll be in town, he’s scheduled to perform three times—as a member of the Allman Brothers Band at the Municipal Auditorium on Friday, April 23, and then the next day at the Fair Grounds, both with the Allmans and fronting his own band. Both groups are kicking off their summer tours with the Fest, and Haynes will showcase material from his new sol...