I didn't make it to Ondrej's JT workshop but Ondrej was up here in Seattle at the very end of August for a concert and workshop. In deciphering my very sloppy notes, here's what I got.

There are four engines the drive Ondrej's didgeridoo playing. They are:

1. Diaphragm which equals the bass drum
2. Throat which is your signature sound with vocals
3. Mouth (tongue, jaw and cheeks) which equals the tom drums and snare
4. Lips (sorry didn't get any details on this one)

This is how he gets the layering. As for speed, he breathes on the trumpets (so much my theory for of him breathing through his ears). It's hard to describe the technique exactly but I'll do my best. The trumpets are a diaphragmatic push and through a tight embouchure, not a spit trumpet, at the same time doing a bounce breath. Mike Jackson does the same thing in his playing.

Ondrej divides the tongue movements between front and back going from hard to soft sounds:

Front sounds are "t, d, r, n, s"
Back sounds are "k, g, ng, and ch (like the Hebrew "ch" [like something's caught in the back of your throat])

You can use these combinations of sounds to make the rhythms--Ondrej gave us insight that he uses tk (like ticka) and vk (like vicka with "v" part done as a trumpet as described above) a lot.

Some of the combinations he gave to us are:

1. tk tk vk tk tk vk tk vk
2. tk vtkv tv (this one's a doozy)
3. kt vktv kv (so is this one)
4. tkv tkv kvt

Any of these can be made softer by using different front and back sounds of the tongue. for example

"tkv tkv kvt" can become "dgv dgv gvd" sounding like.

These are by no means complete notes as we covered a HUGE amount of material so perhaps anyone can fill in the gaps or make corrections as needed. Hope this helps.

Peace,
Pam