Remember these pieces of bamboo which we harvested back in February? (see previous post).
After some measuring and humming and hah-ing, he decided that we should turn one of the pieces (the one on the block in the picture above) into a jinashi shakuhachi, which is one with no filler on the inside. Shakuhachis are broadly categorised into jinashi and jiari, the latter of which are shakuhachis where filler has been added to the inside of the bore and built up to make a more ideal profile, which in turn means a more balanced, focused tone. This process can take several months.
Jinashi shakuhachis are much simpler, though some would argue that making a good jinashi shakuhachi is just as difficult. (My teacher is not one of those people, he once said to me "I don't see the point in Jinashi shakuhachi", but he may have been joking). The shakuhachi is cut from one piece of bamboo and other materials are not added, except perhaps for an internal coat of varnish to prevent mould.
Apart from requiring less time and slightly fewer different techniques, the reason he decided on a jinashi shakuhachi was that the diameter of the bamboo is too narrow for a proper jiari shakuhachi.
First, we shaved off some of the extra root matter from the ends. (Incidentally, today, he did 90 percent of the work, and I couldn't take photos of myself when I was having a go). These are traditional instruments with a long history, but he isn't afraid to use modern tools.
Because the bamboo isn't an ideal length, we decided to cut the bottom-most node off, leaving six. Purists will probably read no further, as shakuhachis traditionally have seven nodes from the mouthpiece to the root end.
Next the bamboo was heated for quite a long time with a heat gun, until it became a tiny bit supple.
Then it was placed in the "bending tool" (a long plank of wood with a large rounded slot cut diagonally into the side) and pressure applied to straighten a couple of bends. Having the bamboo as straight as possible makes it much easier to work with.
Then the extra bamboo was cut from the mouthpiece end...
Further tidying up with the sander.
He then measured the distance from the nodes to the mouthpiece and checked them on a chart on which he had transcribed his "ideal" bore profile. I've decided not to include a photo of the chart here as it has taken him decades of experimentation and minute adjustments to get to this point and it isn't my place to share it.
Once he knew how wide the bore had to be at the nodes, he selected a different drill bit for each node and drilled them through, giving the bore a sort of crude internal structure.
Then it was back to the sander to shave away the mouthpiece to the correct angle. (I'm not one to criticise a craftsman, but if and when I do this I will wear gloves).
Filing and carving the inside of the mouthpiece to open it up a little more.
This is one of many home-made sander bits, which he's attached to the drill to widen the whole mouthpiece to the correct diameter.
This is a bad photo, but it's the only one of him using a little punch to mark the fingerholes.
Drilling the fingerholes...
Tidying up (knife across the grain so as not to split it)
The shakuhachi, finished for now and more or less playable, but as yet with a very crude bore.
Finally, here's a little video demonstration. I noticed that, apart from ロ (RO, the fundamental note of the shakuhachi) the other pitches are more or less in tune with themselves. The honkyoku KUMOIJISHI is unusual in that it doesn't feature the note ロ, so it works reasonably well.
The next stage is the long process of shaving and shaping the bore, which should improve the timbre, and if I'm lucky the tuning as well. Watch this space for updates.