A Sonoma County classic, the Cotati Accordion Festival is in its 21st year of playing, celebrating and giving back through the wheezing sound of the bellows. The festival raises money to support performing-arts programs for local youth, all while raising the spirit of Myron Floren and clustering for a group rendition of “Lady of Spain.” This year’s extravaganza features Those Darn Accordions, Polkacide, the Mad Maggies and many others on Saturday and Sunday, Aug. 20–21, at La Plaza Park. Old Redwood Highway and West Sierra Avenue, Cotati. $15–$17. 9:45am–8:30pm.www.cotatifest.com.