The Del Sol Quartet returns to Old First Concerts to host its 3rd annual festival—The Pacific Pythagorean Music Festival—highlighting the experimental innovators and traditional masters of pure-ratio harmonies. Although the Bay Area has long been a hotbed of alternate tunings, the Pacific Pythagorean Music Festival is the first local event dedicated to hearing these resonant harmonies. This year's festival, Modes of Changes, highlights Persian scales with the world premiere of Reza Vali's String Quartet No. 5, ‘Gavesht’ with a pre-concert talk on Vali's new alternate tuning music software. The Del Sol Quartet set will also include the world premiere of Madeline Ashman's Gravitation. The festival also includes performances by Ken Ueno with Viola Yip & Hafez Modirzadeh with Keshav Batish.