The Boston-based ensemble 3 Play+ makes its CD debut with American Waltz, a contemplative set of melodically-grounded compositions and free-form, high-energy explorations. Co-led by pianist Josh Rosen, who is the group's main composer, and bassist Lello Molinari, the quartet performs with openness to each musician's distinct voice, creating a unified concept that is able to veer off course into fresh musical landscapes.

The disc is full of divergent, genre-bending musical portraits. The opening title track, for example, with its plaintive mood, stands in stark contrast to the bombastic group improvisation of "Happy Cramping." Rosen's lyrical "How Do I Know What I Don't Know?" has hints of a pop-jazz flavor without being overly sweet. The piece suits well the singing quality of trumpeter Phil Grenadier. Drummer Marcello Pellitteri performs with strength and agility on the blazing "Be a Battery," a wide-open piece featuring intuitive blowing from Grenadier, Rosen and guest saxophonist George Garzone.

Molinari takes on a convincing melodic role on the harmonically-rich ballad "Old Fashioned." The bassist cleverly moves from supportive low end growls to horn-like lead lines, playing a friendly game of back-and-forth with Grenadier. A compositional highlight for Rosen is the odd-metered "Soupy's Comin' Home," with layered rhythms and themes. The pianist turns the tune's solo section into a swinging, open jam with inspired results.

The epic closer "Bulletrain" morphs in myriad ways, with guest guitarist Mick Goodrick leading the charge. The tune eventually finds its way with a funky minor groove and hooky theme. At ease with risk taking and allowing the musical deck to be continuously shuffled, 3 Play+ proves to be a group worth taking a chance on.