DANCE: Come learn the polka at the Yerba Buena Gardens Festival's open-air dance party at Jessie Square with Big Lou’s Polka Casserole, who are devoted to reminding audiences that polka was once rock 'n roll for Eastern European immigrants and their descendants.

6 to 7:30 p.m. // Jesse Square (Mission, between 3rd and 4th St) // free

COMMUNITY: The Divisadero Art Walk is "back and even better" with its sixth installment. Thirty-six galleries, restaurants, bars, cafes, and retail shops will be participating, many of them offering special deals, including free hatha yoga at Yoga Tree, $1 oysters at Bar Crudo, and drink specials galore.

5 p.m. to Midnight // Divisadero Street from Haight to Geary // free

FASHION: The Academy of Art's School of Fashion presents Styling: Dressing the Fashion Image, featuring the work of aspiring stylists and their collaborations with student photographers and fashion designers. The exhibit runs through September 30th.

5:30 to 8:30 p.m. // Academy of Art Gallery (688 Sutter St) // free