Walt Blanton/Tony Branco/John Nasshan: Monuments

Listeners who associate the concept of free improvisation with harsh chaos or impenetrable obscurity will be pleasantly surprised by this Las Vegas-based trio, which wanders amiably through seven open-ended yet even-tempered pieces. This grounding is largely due to drummer John Nasshan, who sticks closely to bop-based rhythms and keeps even the knottiest excursions in the pocket. Branco’s piano pulls in the opposite direction, with deep introspection suggesting modern classical music, while trumpeter Blanton holds the middle ground, balancing tuneful ruminations with bursts of dazzling invention.