The Xiao, which is an ancient Chinese vertical flute and also my favourite musical instrument, has gained interest from all over the world recently. There have been English tutorials on Xiao on Youtube, some English books for Xiao on Amazon and some makers of Xiao from the United States over the past decade, but it is still not as popular as Dizi or Shakuhachi worldwide, let alone compared with the western concert flute. Generally, the versability of Xiao has been underestimated, both in and especially outside China.
Recently the social media platform Reddit, there was a question raised by someone who was going to compose a piece of music for the Xiao flute and asked if it is possible to play all the 12 chromatic notes with one Xiao flute. A few people answered the question and said that it was impractical to play all the chromatic notes on Xiao before I posted my answer that it was in fact possible although challenging to play chromatic scales on a Xiao by covering half holes for some notes.
Geoffrey Ellis is a well-known keyless flute maker living in the United States, who also makes Xiao. On his website, there is such a statement as an introduction to Xiao, “The length of the bei xiao ranges from around 24” for the smallest xiao up to 36” and it has more than a two-octave range. Skillfully handled it will play four notes of the third (altissimo) octave. Very skilled players can (technically) achieve fully chromatic play by the use of half-holing, though such notes are not as strong as open-holed notes, and in particular, the second note (Eflat on a D/G xiao) will be very anemic when achieved through half-holing. Because of this it is not really considered a viable option.”
I just want to comment on this statement. Nowadays the Xiao should easily reach two and a half octaves, while skilled players can play the full range of three octaves on a well-crafted Xiao. I have tried that I can play the full range of three octaves on my Xiao made of plastic though I am just an amateur level player. By the techniques covering half holes, it can play chromatic scales. However, the techniques of half hole covering should not merely be a technique of finger movements, but also the control of the breath. Master Winson Liao has a tutorial online for the half-hole covering technique. Based on his technique, a player should also blow downward to the Xiao and in this way the half hole can be opened larger. Here we should note that half hole covering here means to cover some part of the hole, not exactly half of it. The principle here is very simple. The pitch will be turned down if one blows downward to the Xiao flute so that the half-covering hole can be opened larger to maintain the accuracy of the pitch.
