Organizers announced the lineup Wednesday for the six-day, street festival that runs Aug. 27-Sept. 1 at Victorian Square.

Osborne is a seven-time Grammy nominee whose hits include “Shake Your Hips” and “What if God Was One of Us.” She’ll play that Friday night and classic rockers Jefferson Starship on Sunday night.

Other acts include country favorite Joe Diffie, Boston-based singer-songwriter Eric Hutchinson, the alternative rock band Lit and the funk and soul artists Robert Randolph & the Family Band.

All shows are free.