Tom,
This is perhaps more a linguistic than an acoustic question, but can the Bawu justifiably be termed a "free"-reed instrument?
In my view, a free reed - whatever its nationality - has its set pitch, defined by the maker of the instrument, which is "free" from the influence of the player (apart from slight nuances, e.g. "bending"). The reed of the Bawu is no more free than that of the European clarinet, oboe or bagpipe, or the various Oriental shawms, and we call these simply "reed instruments".
Even using the term "free reed" for metal tongues doesn't work in a European context. A Russian friend of mine has a sort of hornpipe with a metal tongue mounted in a metal mouthpiece, fitted to a wooden tube with six holes. The fingering is like that of the tin whistle, and the single reed yields the whole compass of the pipe. That would be a European equivalent of your Bawu, but I wouldn't call it a free-reed instrument.
Cheers,
John
This doesn't match my definition of free reed. For me, a free reed describes the reed of the instrument, not the instrument itself. Traditional western reeds are either a single reed or a double reed. A single reed makes sound by beating against the mouth piece and a double reed makes sound by beating against a second reed. In a free reed, the reed isn't actually hitting anything, it's vibrating in a frame. In this manner, the reed of a Bawu is free.