Behind closed doors in Tibet Temples - a long tradition of very long trumpets - is passed on only orally and strictly private.
Fascinating Instruments, specific playing technique, and various notations are taught only from masters within temples.
Afraid of the low sounds, the temple are safe places for tibetians, their king and the Buddhist.
First time, austrian & chinese researcher demonstrate scientific facts behind the sound and its tradition. 2012 (c) Prof. Dr. Yu-Hsiu Chen, Dr. Johannes Wollein & Prof. Dr. Matthias A. Bertsch