I think it was Huddie Ledbetter ( leadbelly) who said about folk music " I ain't never heard a horse sing" and so it is with the folk flute. The folk flute is as the folk flute does and any flute in the hands of a musician playing music, learned from his elders without formal tuition, must be said to be a folk instrument. When I first went to study flute making at what was then the London Furniture College, now the London Guildhall University, the beginners project was a folk flute designed by David Armitage, then head of the woodwind department. A basic flute in three parts of near equal length with no fancy turnery or ornamentation, not even a cap to cover up the cork. But the potential playability of this instrument was excellent, so lesson number one , intentional or otherwise, was that the best instruments are not to be judged by appearance, price or exclusivity but initially, at least, on performance. It may be therefore deduced that what is seen to be a folk instrument need not be one of poor musical quality. It has been written by one well known recorder maker that the penny whistle is a "useless folk instrument" and so when asked by those who knew me when I was beginning as a flute maker " how is it going" I usually respond with " Oh, you know, making a living out of useless folk instruments". The universally recognised difficulty of making a living as a flute maker helps them to understand that those folk instruments are not so useless after all and that there is a future in producing them to the very highest standard, this is after all what all musicians expect.
The shakuhachi flute from Japan is a good example of a folk flute taken seriously and is made today by modern techniques involving cutting the bamboo in half to shape and polish the bores as well as by traditional craftsmen making them in one piece as was originally done. The instrument is used today in Zen Buddhist meditation and also in Japanese classical music and sometimes jazz as well as its role in the Japanese folk music tradition. In north America the native Indian flute is as popular today as ever with makers at all levels of sophistication making instruments that range from traditionally hand crafted ones bound with sinew and leather to hold the separate parts together through to mass produced, highly polished models with a much more 21st. Century look. The instruments deliver a basic pentatonic scale but can be cross fingered to produce all the notes of the chromatic scale. They are in great demand today and are exported world wide to people who use them for creating their own background music as well as those who play for film and TV The flutes which I make are based on instruments from the classical era and were originally made for the concert flautist of the time, they are, however, used today by a variety of musicians who play music from the Baroque, on the one keyed instrument, through folk musicians of all backgrounds, to players of classical music for recordings, films and TV It is the most rewarding occupation I have ever had and I have no objection to them being described as folk flutes. To those who think I am wrong I say "come and make folk instruments and you will find out how demanding those musicians can be" .
Any instrument that produces sound by having air pushed through it (usually by blowing) is a wind instrument.