On Tuesday May 4 at noon, Alegres de Coalcoman [All-egg-rays de Co-all-co-mahn]play traditional acoustic Mexican music to mark the opening of Concord's 22nd Annual Music and Market Series.  The free outdoor concert and film series runs through September 16, at  Todos Santos Plaza, Willow Pass Road and Grant Street, in Downtown Concord. For more details call 707-869-9403 or visit www.communityconcerts.com.