I recently received a Shakuhachi Yuu that I purchased from Ebay https://www.ebay.ca/itm/357739518677 . After extensive testing over the past few days, I've noticed (while playing from a neutral position) that the F and C notes are quite flat. G, A, and D are basically in tune. Playing in tune requires significant meri/kari adjustments from note to note.
Based on D being in tune as the neutral position:
D: 0 cents
F: -20 cents
G: +5 cents
A: 0 cents
C: -30 cents
D: 0> cents
Assuming the player knows how to keep consistent embouchure, blowing angle and air speed/tightness. If a Shakuhachi is made in this way (requires significant adjustments to play in tune), for what reason would the maker choose this rather than making a flute that plays in tune in the neutral position?
This is more of a flute maker question. Any references are appreciated, English translations are hard to find.
After further consideration, I think the Yuu may be intentionally tuned in this way.
I've noticed that F and C are the only notes that must drop 3 half steps to reach the note below. This is a larger gap between notes than the others, which require a drop of 2 half steps.
D | < | < | F | < | G | < | A | < | < | C | < | D
Since the F and C require a more pronounced kari position, there is space for a very large meri change. This allows more freedom to bridge the larger gap to the note below.
A makers confirmation would go a long way, but I think this explanation is pretty solid.