The first reference to the legendary sounds of Gurtu was made in 1956 by an unidentified musicologist who was trekking thought the foothills of northwest China. He heard unearthly sounds he later identified as the 'songs' of a groups of nomadic Monks calling to their herds of yak across the hills. He identified their similarities to the Balinese Pelog [an effect no doubt enhanced by the rhythmic chimes of the bells around the beasts’ necks] and made a few crude field recordings. 

But before he could return with more advanced recording equipment, the Monks had continued their  wanderings.  At some point there seems to have been a shism within the group -  half left to continue their aimless travels within China and the other group left for India. Only a generation later did they finally manage to regroup in the UK, many with extended families in tow. It is speculated that the geographical separation they experienced over that period is the cause of the two tonal Gurtu variations – the more northerly “Bh’en Gyo” technique and the softer, western “Kha Meli”.

Sadly the quality of the 1956 field recording is so poor as to render it impossible to say which technique is more reminiscent of their original vocal dialect. But both have their fans – some praise the “Bh’en Gyo” for being charismatically out of tune (particularly at the start of songs) while others prefer the less structured “Kha Meli”, and its seeming reliance on intoxicants.

Bh’en Gyo chanting is similar to western "rounds" singing: one monk will start the chant, quickly changing pitch until a harmonious tone is found, and the others then join in, usually using deep sonorous tones. On the other hand "Kha Meli" chanting is a freer, more joyful vocal style with many characteristic tics: yelps, cries and rhythmic noises.

It is when the two are combined that the listener is able to experience the full Gurtu sound.