What actually happens while practicing circular breathing has already
been covered by other writeups, so I won't repeat that here. I have
however found these writeups regrettably incapable of teaching me how to
accomplish this apparently incredibly difficult feat. There seemed to be
so many things going on simultaneously that I didn't know where to
start.
Here is what worked (works?) for me, while learning to play the
didgeridoo. Consider this writeup a work in progress, as I've only just
begun practicing.
It is assumed that you already know how to produce the basic drone, just
that you don't have enough breath to keep it going indefinitely.
First, alternate between producing a drone and taking that snatch of
air in through your nose. Forget about that whole
air-blown-out-from cheeks business for now. The sound should be similar
to the line-engaged signal, thus:
drone ----. .----. .----. .----. .
| | | | | | | |
| | | | | | | |
no drone `-' `-' `-' `-'
I find that a frequency of 160 cycles per minute works best for my lung
capacity.
Your task now is to smoothen out the valleys where the instrument is
silent. You know the drill - keep your cheeks puffed while you exhale,
and squeeze it out while you inhale. If you've got the basic rhythm down
now, doing these two things in sync shouldn't be too hard. Now you can
practice keeping the instrument humming for a larger and larger part of
the period where you breathe in, until the gap is completely bridged.
Now try varying the pressure in the two phases of the cycle, and see if
you can make them match up better. This stage is the one I am at right
now.
The main difficulty with circular breathing seems no longer to me to be
managing to breathe in and blow out at the same time. What I've
discovered, is that this technique is actually physically exhausting. I
don't think I'm doing anything wrong; another writeup mentioned that the
best players could presumably keep a continuous drone for up to 10
minutes. It's taxing on the cardiovascular system, and it seems that
the velum gets tired by quickly opening and closing -- at least
mine starts to hang down after a while, making it feels as if I'm
snoring. A rather unpleasant feeling to have in waking life, if
you ask me.