Once a strictly blues festival, the Santa Cruz Blues Festival has come to encompass a wider range of music in the past decade or so, including rock ‘n’ roll, soul and roots music. It’s what organizer Bill Welsh describes as “American blues-based music.”

Now in its 22nd year, this year’s lineup, which will perform May 24-25 at Aptos Village Park, includes rock ‘n’ roll legend Gregg Allman, who will be headlining Saturday, and throwback crooner Chris Isaak, who tops the bill Sunday.

There is a lot of fresh talent at this year’s festival, both in terms of SCBF first-timers, and some old favorites debuting new projects. Even Greg Allman surprised people recently when he announced that he would be retiring the Greg Allman Brothers at the end of 2014. Dave and Phil Alvin, who got their start together in the Blasters, will be bringing the music of their new album Common Ground, their first collaboration in 30 years, on Saturday. Their performance at in Aptos will be the live debut of these new songs.

“We’re just trying to keep it going for another 22 years. Every year we try to book relevant artists that will skyrocket into the future. Chris Isaak and Greg Allman, the people in Santa Cruz are familiar with them.  But we always try and stack it up with some newer talent, stuff that’s hopefully going to be setting the standards for the future,” Welsh says.

Sunday’s lineup includes nothing but SCBF first-timers—including Isaak. Opening up Sunday is Serbian blues guitarist/singer Ana Popović. She’ll be followed by Rich Robinson, guitarist and founding member of blues-rock band the Black Crowes, who’s been a solo artist for the past 10 years. Performing before Isaak is Vintage Trouble, a southern soul-blues-rock quartet that has been on the rise since forming in 2010.

Saturday’s lineup is a combination of new and old artists. Allman is a Santa Cruz favorite, as are the Alvin brothers. But gospel-inspired rock singer Nikki Hill, who opens Saturday, and Delta blues/Cajun guitarist Tab Benoit, are both first-timers at this year’s festival.

“Usually we have a new act open the festival, someone that we think is going to be leading the way in the direction of the music that they’re playing. Nikki Hill is breaking out all over the country right now,” Welsh says.

Funk-jazz horn player Trombone Shorty, who is main support to Greg Allman on Saturday, actually had that same opening slot seven years ago as the up-and-coming new musician, and has since gone on to great things. He started out at the bottom of the festival bill, says Welsh, and “now he’s close to headlining.”

The Santa Cruz Blues Festival will be held at Aptos Village Park in Aptos on Sat-Sun, May 24-25. Festival starts at 10am both days.