Mujitsu and Tairaku's Shakuhachi BBQ

Hey everyone....

I've been listening to a LOT of honkyoku lately and i've noticed that there seem to be certain combintations of intervals/notes
that are played more often than others. 

such as Ha Ro, or Tsu Re....

is there a (somewhat) complete list of "must know" intervals that pop up a lot in traditional music?

I'm practicing Ha Ro quite a lot and find that isolating that inverval alone has worked well. 

I know, i know, ideally in a perfect world we should practice them all..... but how about a short list of "uber important intervals"

thanks in advance.

jacques