Mann and Collette keep swapping instruments and roles, making constant variety the whole point of the session.
Early in his career, Herbie Mann made Flute Fraternity (1957) as a statement of what two skilled multi-instrumentalists could do together in a studio. Working alongside Buddy Collette, Mann explores the lighter side of bebop — nothing heavy, nothing designed to prove anything except that two flutists (and saxophonists, and clarinetists) could keep a session moving through sheer inventiveness. The rhythm section, anchored by Mel Lewis on drums and Buddy Clark on bass, stays loose and responsive, never getting in the way.
The selling point here is the constant switching. Scott Yanow in AllMusic nailed it: Mann and Collette are constantly trading off lead voices across their various horns, which keeps the music from settling into any one groove for too long. Some listeners find this refreshing; others, as The Penguin Guide to Jazz Recordings noted, feel the parade of different instrumental combinations dilutes the impact. It depends whether you want a record that stays focused on one idea or one that treats a session like a conversation where nobody sits down for long.
This is lightly swinging music without pretense — no one's trying to reinvent jazz here, and that's fine. Mann would go on to explore flute in many directions, from bossa nova to world music experiments, but Flute Fraternity catches him at a moment when he and Collette simply wanted to see what two versatile players could accomplish together in an afternoon. It's solid small-group jazz from a musician still finding his voice.