Having shown tremendous fire and focus in settings from quartet to big band to wind ensemble, alto saxophonist Miguel Zenón partners with the Spektral Quartet for a bona-fide chamber-music outing. Drawing on folkloric forms and traditions from the countryside of his native Puerto Rico (not unlike his 2005 jazz quartet effort Jíbaro), Zenón embodies an under-recognized hybridizing impulse within classical music that goes back centuries. While string quartet played a role on his 2008 album, Awake, Yo Soy la Tradición departs from jazz instrumentation altogether, relying solely on the haunting, beautiful blend of strings with the composer’s fleet and lyrical alto. The music is staggeringly ambitious, steeped in modern classical language and logic yet bearing the rhythmic imprint of jazz. There is room built in for the leader’s improvising horn, but the highly complex written material requires him to function as a fifth quartet member, nailing deft unison passages and close contrapuntal details with an unperturbed grace.