Grammy-nominated artist Ledisi will be one of the star attractions at Saturday’s Berklee Beantown Jazz Festival. Ron T. Young PhotographyThis Saturday jazz aficionados will converge on the South End for the 15th annual Berklee Beantown Jazz Festival (BBJF). The free, all-day outdoor event will resound with contemporary jazz, funk, Latin, pop, and soul acts on three stages. “Jazz: the Voice of the People” is this year’s festival theme.

“Jazz is a universal language that unites cultures and brings communities together,” said John Hailer, president and chief executive officer of Natixis Global Asset Management, the presenting sponsor of the festival for the fifth year in a row. “As one of the world’s premier cultural centers, Boston is a natural home to showcase this amazing American musical tradition, and we are proud to partner with Berklee again this year.”

The BBJF —Boston’s biggest block party—takes place from noon to 6 p.m., on Columbus Avenue between Massachusetts Avenue and Burke Street in Boston’s South End. The outdoor performances, which have drawn as many as 80,000 music fans, are open to the public free of charge. Check berklee.edu/beantownjazz for updates and a full schedule of events.

Headliners include nine-time Grammy-nominated R&B artist Ledisi, who recently portrayed legendary gospel singer Mahalia Jackson in the Martin Luther King, Jr. 2014 biopic “Selma.” Among the other big draws are tenor saxophonist Javon Jackson, with legendary drummer Jimmy Cobb; the Mosaic Project, a collective led by three-time Grammy-winning drummer and producer and Beantown artistic director Terri Lyne Carrington, with Philly-based soul/R&B vocalist Jaguar Wright; singer/songwriter Paige Bryan; rising funk bassist Alissia Benveniste and the Funketeers.

Faculty and alumni also play a major role with performances by faculty artists George Garzone with the Teros String Quartet; Eguie Castrillo and the Palladium Nights Orchestra; Omar Thomas Large Ensemble with Stefon Harris; David Gilmore and Energies of Change; Marty Walsh and the Total Plan; and alumni acts Caili O’Doherty; ChoroBop; Carlos Averhoff Jr. and iRESI featuring Francisco Mela; and Felix Peikli and the Royal Flush Quintet.

The Natixis Family Park at the Berklee Beantown Jazz Festival will transform Carter Playground on Columbus Avenue with activities including inflatables, face painting, and an instrument petting zoo staffed by Berklee professionals. The park will also host KidsJam, an interactive program led by Berklee’s Music Education Department that introduces young children to a variety of musical activities, including singing and sound exploration, playing rhythm instruments, and creating, listening, and responding to music.

The Berklee Beantown Jazz Festival has become a major cultural landmark in Boston, offering attendees “the sort of hard choices people have to make at Newport and other top festivals,” according to the Boston Globe. The festival was founded by Darryl Settles, owner of Darryl’s Corner Bar & Kitchen and president of D’Ventures Limited, and has been produced by Berklee since 2007.

For the sixth year in a row, Berklee has received a grant from the National Endowment for the Arts (NEA) to support the festival and its theme. In awarding the Art Works grant to Berklee, the NEA cited the festival as a celebration of Boston’s diversity as reflected in the attendees, music, food, and crafts.