On an odd ball search I found a site that sells Shinobue, Ryuteki, Nohkan and Shakuhachi. The site had short lessons and some sound clips. Watching the Shinobue tutorial, I thought it was interesting how they approached holding the instrument and the singing mnemonics (shouga?) used to teach the tones that will be played.
Anyway enjoy if you are so inclined.
It seems that the links are internet explorer only
http://www.mejiro-japan.com/system/index_e.php?c_id=504
Not that I will run out and buy a Shinobue, it just means that I will try to play Sakura on a fife.
Notes to myself and speculation…
http://www.asahi-net.or.jp/~DL1S-YMGC/fuenok-e.htm
The shinobue seems to be the least refined, having a non-tapered body and fingering similar to that of a fife if you ignore the seventh finger hole. It seems that it is set up to play in the first two octaves, but has a relatively narrow bore (Instructions for the 7-hon shinobue above lists the bore at 11mm) and should play easily in the third register.
The Ryuteki seems to be an improved Shinobue. Made with bamboo that is treated to be harder and having a tapered body (no doubt to help intonation). It looks to be a more refined instrument.
The Nohkan, seems to be made in much the same way as the Ryuteki, but has a constriction in the bore. Due to a restriction in the bore between the embouchure and the first finger hole, the overblown notes are different than a normal cylindrical flute. For a c flute, over blowing C produces D and F instead of C and G (or so I have read).