The Twin Cities Jazz Festival — maybe the world’s only jazz fest with a “river” running through it — will celebrate 20 years of staging free, world-class music this weekend in Mears Park.

Oh, and admission is still free.

Twin Cities-based pianist-composer Javier Santiago and his combo will kick things off on the main Mears Park stage at 4 p.m. One of the festival’s featured performers, alto saxophonist Tia Fuller and her quartet will follow at 6 p.m. At 8:30, one of the most recorded tenor saxophonists in jazz, the veteran Houston Person, will take the stage. Person will collaborate with one of the brightest young pianists in jazz, Emmet Cohen, and his trio.

Saturday’s main stage headliner at 8:30 p.m. will be three-time Grammy award-winning vocalist DeeDee Bridgewater with the Memphis Soulphony, who helped out on her 2017 album “Memphis …Yes, I’m Ready.”

Preceding Bridgewater at 6 p.m. will be rising star vocalist Nayo Jones. A Chicago native now based in New Orleans, Jones tours with trumpeter Kermit Ruffins, and also performs with the New Orleans Jazz Orchestra.

Other mainstage performers on Saturday include the Walker West Music Academy combo at 2:30, and Patty Peterson presents the Jazz Women All-Stars at 4 p.m.

The free festival will also host music on two other outdoor stages, on Fifth Street and at the Union Depot, plus 13 indoor venues, in and near downtown St. Paul. As he does every year, New York-based pianist Jon Weber will host a festival jam session starting about 10 p.m., at Vieux Carre, 408 St. Peter St., St. Paul.

For details, go to twincitiesjazzfestival.com.