Hi folks!.
Since I heared some japanese cd versions that start Jonkara Bushi with Rokudan´s Ichidan, I asked Kyle about the relationship between Rokudan and Jonkara Bushi.
He answered me that all the forms of Jonkara are based upon the first part of Rokudan.
Somebody has some information about the history and “standardization” about this relationship?.
And why Rokudan is not between the “Godai Tsugaru” if JRokudan Ichidan is the base of Jonkara??.
Thank you guys!
Best Regards!
Bruno
P.D: I hope you enjoyed my shakespearean English… 
Yeah, Gerry’s the man to talk to about this. After writing his masters (Phd now?) in the history of tsugaru shamisen, you could say it’s his thing.