Contrasts — those both real and imagined — have been a theme in saxophonist Diego Rivera’s work since he first arrived on the scene in the 1990s. As a composer and arranger, he is known for crafting melodies that balance brawny, self-propelling drive with lithe, balletic grace. Stylistically, he has made it his mission to walk the line between jazz and the music of his Chicano heritage, identifying points at which they overlap and, even better, complement each other through their singularity. His latest album, Mestizo, plays up to these strengths, amplifying all voices in a potent mix of styles without watering them down. “Rasquache,” which in Chicano slang refers to the attitude of the underdog, is an example of Rivera’s idiom-making at work. In Rivera’s melody — not to mention the incandescent drumming of Rudy Royston — one hears multiple conversations: between the musicians, definitely, but also between cultures and across time.