Very important observation about breathing and non written music... breath is a gesture as is speech or playing an instrument... Some gesture can be written some others not, the flow in time and his cycles created a time dimension proper to music and not to metronome measured by the clock time...
I own 20 albums of didgeridoo, not one is like an other...
This music may be very powerful...
Didgeridoo players can breathe continuously into the instrument while ’talking’ to create an incredible variety of sounds. Clapsticks (hundreds of them) and didgeridoo featured in the opening work of the refurbished Sydney Opera House, in "Of the Earth" by Willian Barton. I cannot conceive how music for the didgeridoo can be written down!