Mujitsu and Tairaku's Shakuhachi BBQ

I have a group of scores that are Buddhist hymns on shakuhachi.  Does anyone know much about these songs?
I have them from two groups it seems and a few others. 
Those being the Yamato-ryu　and Kongo-ryu.  I've figured out that the Kongo-ryu is from Koyasan Shingon-shu.  I found that you can take classes there to learn how to sing the songs. 
The Yamato-ryu is also Shingon-shu.  If anyone knows where to find recordings with shakuhachi, that would be interesting to hear.
I also just found a recording for a Nanzenji-ryu Buddhist hymn, which uses koto and shakuhachi.
http://www.youmeiin.net/common/goeika.html

Here is also a site that has the different ryu/ha groups.
http://www.xn--24tr3x67y.com/index32.shtml

Chris