by Gabe Meline, Senior Editor KQED Arts & Culture. Calvin Keys, the Oakland-based jazz guitarist who worked with giants like Ray Charles and Ahmad Jamal, and who possessed a unique style both on stage and records, died Sunday afternoon. He was 82 Keys was surrounded at Berkeley’s Alta Bates Medical Center on Sunday by family and loved ones from the Bay Area music scene, said his close friend and musical collaborator, Art Maxwell. The cause of death was complications due…