Farting: has anyone ever truly mastered the 7 note change?

Question:

Farting: has anyone ever truly mastered the 7 note change?

Best Answer - Chosen by Asker: That is pure amateur status,I can not only master the seventh note change but have reached the eighth note which really is an achievement however, you have to make sure there are no windows or glass around.
The secret is to not let all the gas escape too much at one time and to position your cheek butts close to something that will give you some kind of echo.
I even get the dog to howl along with me although, I don't know if he is just getting gassed or if he is just doing it for the fun.