The (th)Underkick is a technique of parallel playing, done by diaphragm, to make another rhythm underneath the surface rhythm played with voice, tongue, cheeks or another front articulator of your body. What it means is there is a strong feeling of (at least) two independent rhythms going on. If voice is included, this technique becomes considerably more challenging.
The easiest way to explain it is on the 8/8 rhythm. There are two most basic manifestations of this rhythm categorized by the place which is stressed.
One is the 3-3-2 rhythm and the other is the 2-2-2-2 rhythm. To be more precise, we will write them like
123 123 12 and 12 12 12 12
They last the same amount of time, so you can count one over the other.
The first step is to try to “sing†one and clap the other. You can try it in both versions. In this example the articulations of the 3-3-2 rhythm are small articulations, like tongue articulations, and articulations of 2-2-2-2 are big articulations, like diaphragm articulation. A combination of the two rhythms would look something like:
123 123 12
If done in a certain way, this will remain to sound as BOTH of your rhythms. Let’s listen to a few examples.
An example of this 3-3-2 rhythm can be found in the first strong beat in my song Korvo Eksaltiko.
A bit different example can be found in Mandala. The melody of Mandala is in 12/8
Something like
123 123 123 1__, but to keep it simple we will write it as a phrase 123 123 123 123
By adding the underlying diaphragm beat, we will get 123 123 123 123
Now, this is done best on canyon didges, both of narrow and wider form. So it is a conical shape, but close to cylindrical, more or less tight.
Why is that important?
Very conical didgeridoos will react to our diaphragm beats with their own interpretation of it, their own kick. Even Fjord didgeridoos have this ability, let alone Volcano or Grotto ones. On the other hand, didgeridoos leaning towards cylindrical form have a more separate spectrum. Their bass is distinct and with lower backpressure, so that one is able to overblow the bass while not overblowing other sounds. This separation is an important factor in making the final sound picture strongly parallel.