What do Jimi Hendrix, Mildred Bailey, Link Wray and Charley Patton have in common? Native American ancestry. In their new documentary "Rumble: The Indians Who Rocked the World," executive producer and co-creator Stevie Salas and director Catherine Bainbridge explore the often overlooked contributions of indigenous musicians to American music.  "Rumble" opens July 25 at Film Forum (209 W Houston St., between Varick St. and 6th Ave.). Director Catherine Bainbridge and Executive Producers Stevie Salas and Tim Johnson will appear for a Q&A at the Film Forum on July 26 at the 7 p.m. show. Catherine Bainbridge and one of the film's subjects, musician Rhiannon Giddens of the Carolina Chocolate Drops, will also appear on July 27 for a Q&A at the 7 p.m. show. This segment of "The Leonard Lopate Show" is guest hosted by Manoush Zomorodi.