Members of the Santa Fe Opera Orchestra, along with American and international musicians, will appear in various unexpected combinations as the second season of Chamber Music at San Miguel Chapel (401 Old Santa Fe Trail) begins with the first of six Saturday afternoon programs at 3 p.m. on July 13. The opening concert features a trombone quartet called the Four Isotopes. They will perform works ranging from J.S. Bach to contemporary English composer Jeremy Dibb. The next three Saturday concerts: Les Trois Amies playing French music for flute, harp, and bassoon ( July 20); the early-music ensemble Archipelago ( July 27); and three centuries of works for marimba, flute, and bass clarinet with Duo Zuber (Aug. 3). Tickets are $20, 17 and under are free; facebook.com/chambermusicatsanmiguelchapel.