Mujitsu and Tairaku's Shakuhachi BBQ

Hi, Im a little confused as regard the root note of a piece.
I happen to be totally taken at the moment with 'Hon Shirabe'
I understand this is Dokyoku style honkyoku.

but in listening to it with the idea of choosing a certain key shakuhachi to play in a sound bath with particular drones, I hear the root of the piece as 'Re' not 'Ro' - is this right?
perhaps my indian training has fixed my way of hearing but when a 'D' flute plays this tune, using 'D' just hovers rather than fits like a root note would. and i can't get my ears to accept 'Ro'  as the root of the piece!
I have the famous Kohachiro Miyata version which is apparantly played on an 'A' and A as a drone just won't sit for my ears.
am i going slightly mad here or do some pieces use other notes than 'Re' as their roots
or does it not work like that at all?!!

I will go back and listen to the version on Baraka (not on the soundtrack album) as this is the original recording mixed with Synths doing drones BUT maybe thats not neccesarily traditionally correct either?
are we hearing it upside down as western and root note trainedears?
but its probably what I'm hearing as that was my first source of shakuhachi music too.

then of course the next question, if the 'root' (should that even be a relevent point in traditional honkyoku) is other than 'Ro' tehn do different pieces have different roots. i.e. are they based on Tsu, Re, Ri as well as Ro?
I guess I'm so used to Modal instruments and some verymuch fixed root notes for certain instruments I may be 'stuck' in my approach?

a beginner learning,
thank you in advance for any light shed!
Storme
www.earthsong.co.uk