For 25 years, Mainly Mozart has presented concerts, events, and programs south of the border as “Mozart Binacional.” A three-day cross-border anniversary celebration kicks off at the Balboa Theatre in downtown San Diego with a performance of the Mainly Mozart Festival Orchestra conducted by Music Director Michael Francis on Saturday, June 17, at 7:30 p.m. The Festival Orchestra will be joined by Mexican pianist Jorge Federico Osorio as guest soloist, performing Beethoven’s Piano Concerto No. 1. A half-hour Overture mini-concert preceding that evening’s performance will feature Mr. Osorio performing Mexican works, beginning at 6:30 p.m. The Mainly Mozart Festival Orchestra performance with Jorge Federico Osorio will be repeated the next night, Sunday, June 18, at 7:00 p.m., at the Centro Cultural Tijuana. Also featured will be a side-by-side performance of Mozart’s Eine kleine Nachtmusik with Tijuana student musicians prepared by Orquesta Juvenil, the Children’s and Youth Orchestras of Mexico.