Nathaniel Rateliff & the Night Sweats will headline two days of workshops, a rally and a concert advocating for gun control, all under the title Not One More. The weekend event is put on by Rateliff’s own foundation, the Marigold Project, and was inspired by the national student movement in response to the latest school shootings. Local heroes the Night Sweats are known for their party-starting, foot-stomping, rustic retro-soul. But much of the music’s power lies in Rateliff’s brooding beneath the bright horn lines, which suggests darkness even on a warm dance floor — like a last shot of Fernet long past your limit. The concert also includes performances by Fantastic Negrito (winner of NPR’s 2015 Tiny Desk Contest), Chicano funk band Los Mocochetes, and the Denver Children’s Choir.