An arts exchange program sent tubist Marc Unternahrer from Luzern, Switzerland, to Chicago in 2002. There he hooked up with cornetist Josh Berman, tenor saxophonist Keefe Jackson and drummer Frank Rosaly. The Swiss presence notwithstanding, this band’s spare, plainspoken style of free improvisation owes something, however distantly, to Chicago’s AACM. Horns wheeze and sigh. Harmony happens. The band delivers phrases delicately as if laying them out side by side in a display case; and when they aren’t layering short phrases over one another, they’re all being quiet. All four members seldom play at the same time and much of the foreground is ceded to front line hornmen Jackson and Berman. Jackson drops the poker face and blows hard on the longest, best tune, “Take the Place,” but the real charmers of this session reside in the rhythm section. Unternahrer is remarkably agile on the tuba and-free improv be damned-he’s as likely to run stout counterpoint as he is to dog Berman with an upper-register flutter. All the while, Rosaly builds little cities of rhythm around his bandmates’ earnest phrases.