I, like many classically trained flutists, have developed certain aspects of flute technique that are best described as restraining. These technical restraints are like seat belts to keep me and other flutists from flying too far afield with tone, articulation, and overall quality of sound when performing classical repertoire. This does not really equate with one kind of sound, but more a narrow bandwidth of acceptable sounds. This bandwidth creates a reliable consistency of tone and technique between flutists that is desirable for orchestral playing and the majority of chamber music. Improvisational music, on the other hand, challenges normative notions of technique and tone. Such restraints limit the spectrum of sound possible by the flutist, and therefore also limit the musical interactions possible between the flutist and other improvising instrumentalists.
My alto flute improvisations in the "Demolition Duo" (with drummer Ken Ollis) are helping to liberate me from these learned restraints. It's worth mentioning, that compared to the standard c flute, the alto flute is too long and a little unwieldy (even for me with my long arms), pitches don't sound where you think they will (everything sounds a perfect 4th lower), and articulation can feel a bit sluggish in the lower register. But despite these idiosyncrasies, I'm finding that the alto flute is especially liberating to play as it's helping to shed some light on how I really want to make music: free from unnecessary technical restraints and using the full spectrum of sound.