The idea to tune the pitch field to reach from one's shoulder to the Antenna was fine in ancient times when theremins had a pitch range of only between 3 1/2 and 5 octaves.
Some people like Carolina Eyck who plays an Etherwave Pro which has still 5 physical octaves (and does more via a register transposition switch) teach still this nowadays.
But with the arrival of theremins with wider pitch range (tVox tour around 2004, Etherwave Standard with the ESPE01 extension created by me in 2009), the old tuning scheme became simply obsolete and new ways had to be found.
For the Etherwave with ESPE01, I teach the following:
1.) Do not stand centered in front of the instrument - the space between your body and the pitch antenna is too small and you'll build up unnecessary muscular tension in the left arm to reach outwards for the volume loop. Stand with your belly aligned with the cabinet screw left from the front panel. This will have several effects: The theremin will be at the correct height, so that if your left upper arm hangs vertically down and the forearm is stretched out horizontally, your hand is effortless positioned slightly above the volume loop. Your right arm goes out at a 45° angle (where the breast muscle below the clavicle has minimum tension - moving the arm in- or outwards will increase it) towards the pitch antenna and you might grasp the pitch antenna with an almost outstretched arm.
2.) Do not try to tune the full 7 1/2 octaves which the ESPE01 gives you on an optimally tuned Etherwave in front of you. The tone spacing will be too small and the field will be everything but linear. Tune for best linearity, using the fact that the pitch knob has much less effect in the highest register and much more in the lowest. Start with the pitch knob in center position, "measure" the distance between G4 (1.5 octaves above middle C) and G5 (2.5 octaves above middle C) and find whatever fingering technique which will allow you to reproduce that octave spacing (which is almost invariant in that register, the pitch knob allows to move it a little around, but it won't change the distance much) and which we'll thus call the natural octave spacing of your instrument.
3.) Once you can reproduce this natural octave between G4 and G5, try to report that distance from G4 downwards. Ideally, on a perfectly linear and well tuned instrument, you'll land on G3. Most times you won't at the first attempt, so, use the pitch knob to change the G3-G4 distance until it is equal to the G4-G5 distance. Then again, try to report that octave spacing from G3 to G2 and optimize with a (now smaller) correction of the pitch knob until it is coherent with G3-G4 and G4-G5.
4.) While you move on downwards in the bass register, equalizing the field octave by octave as described above, make always sure that your right hand is never closer that 10cm or 4" to your chest. Besides being that an uncomfortable playing position, your body will have too much influence on the pitch field and your hand movements become less important which feels like a stretched field. That's the moment where you have to move backwards to create additional space without loosing balance and stability. Following Peter Pringle's approach, I recommend standing with the left foot taken somewhat back in relation to the position of the right foot. This allows you to move backwards while keeping your center of gravity between your feet (maintains stability) and your body will roughly move on the same 45° axis towards and away from the pitch antenna as your arm, which makes that your body movement will become intuitive and follow your playing with the arm. In the very low register which the ESPE01 allows you to play, you'll see that sometimes only a fraction of a millimeter turn of the pitch knob will allow you to have an almost perfectly linear and comfortably playable pitch field.
There is only one major caveat. All this is futile if the Etherwave is not well calibrated which can make two bad effects:
Either the G4-G5 octave is already very close to the pitch antenna and will thus be already over-compressed, so that you can't obtain a decent tone spacing within that octave,
Or the overall natural tone spacing of the Etherwave is, for whatever reason, already too small and does perhaps allow you to tune for 6 or 7 linear octaves, but these will all be too small.
In both cases, a meticulous internal re-tuning of the pitch oscillators will help. Part of it is going slightly beyond the original Moog factory specification and extending the pitch range at the top end, so that the "normal" playing range moves somewhat away from the pitch antenna into the more linear area of the field. This can be tricky and requires much experience, because "overtuning" it risks to make the pitch section unstable or even to damage the variable pitch oscillator. That's why I offer my help via Skype or Facetime where I will basically retune your instrument while you will locally replace my hands. Interested people may find and contact me on facebook.
