Think of Jazz on the Hill as a gracious and grooving thank you note from KCSM (91.1 FM) to its audience and membership. The annual free festival at the College of San Mateo features two stages, one devoted to top student ensembles and the other to a stylistically diverse array of jazz-inflected acts. The day starts with suave baritone vocalist Jamie Davis, a veteran of the Basie Orchestra who is equally authoritative delivering ballads and blues. The popular and prolific conga master Poncho Sanchez closes the program with his well-traveled Latin Jazz Band. In between there’s vocalist/cellist Rebecca Roudman’s Dirty Cello, roots and blues vocalist Maria Muldaur, and tenor saxophonist Anton Schwartz, who performs with a talent laden quintet featuring Yellowjackets pianist Russell Ferrante, bassist John Shifflett, trumpeter Thomas Marriott and drummer D’Vonne Lewis (the latter two are recent Schwartz collaborators from Seattle). The Youth Stage in the CSM Little Theater hosts Stanford Jazz Workshop middle school Giant Steps Big Band, a six-piece combo gleaned from the SFJAZZ High School All-Stars, Belmont’s award-winning Carlmont Jazz Ensemble, and the Jazzschool Studio Band, an impressive high school combo under the direction of trombonist/arranger Dave Eshelman that’s set to perform at major European jazz festivals this summer.