For longtime collaborators Denny Zeitlin and George Marsh much of their enthusiasm for music lies in exploration of new terrain. Their recording Expedition finds them continuing their journey into the worlds of sound and spontaneous composition. The music presented is inspired and stylistically varied. There are atmospheric pieces, like “Geysers” and the quietly surging “The Hunt,” and ballad-like ruminations, like the ambient “Thorns of Life” and “Spiral Nebula.” The pulsating uptempo tracks are rhythmically fascinating, like the skittery percussion highlight “Shooting The Rapids” and the driving “Sentinel.” The triumphant “Expedition” is a perfect example of the duo’s goal of creating a succinct composition with direction and arc, all spontaneously in the moment. Zeitlin and Marsh's forward-thinking collaboration spans 50 years. Their connection has only gotten stronger as they have invested themselves in expanding their vocabularies in electric-acoustic and improvised music. Expedition brilliantly displays what two highly attuned and flexible musicians can create on the fly.