~~ slide fast, slide slow, knuckles vs. fingertips ~~
Every precision thereminist wants to play notes that are in tune. When moving from one note to the next, the easiest way to hit the next note is to slide to it slow enough that you can simply stop on the right note. Of course, this sliding is usually undesirable unless you are after a slide-whistle effect!
The alternative is to move fast enough from one note to the next that the slide is not noticeable. However, this requires a precise movement and doesn't afford the luxury of "sliding into the note". Also, move too fast and the music starts to sound stressed -- and to overshoot the notes becomes all too common.
I practice three different note-to-note movements: 1) an audible slide from on note to the next, 2) a quick, snap from one note to the next, and 3) a relaxed yet quick motion from one note to the next. My primary goal for most music is the third alternative -- I practice the other two to "bracket" the third.
The quest to hit notes precisely and fluidly has led me to curve my fingers when going for positions 2 and 3 (although, with my hand's size, I still have to extend my pinkie to get 4th position sometimes). Curving the fingers is really the same as the knuckle extensions that Peter Pringle covers in his excellent DVD.
I had trouble with knuckle extensions at first because my first position was not predictable. Now that I have identified (and hopefully solved) that I have found "knuckle extensions" to be a great way to achieve the other positions.
The advantage of using the knuckles rather than the fingertips is that the finger tips are out at the end of the fingers such that a little bit of hand motion is amplified at the end of the fingers. The same motion, when applied to curved fingers (the knuckles) results in less movement because the knuckles are closer to the hand than the fingertips. Thus, pitch control is easier.
The use of knuckles instead of finger tips allows a more relaxed vibrato -- again, with the fingers curved, it is easier to do a fluid vibrato because a given arm motion results in less movement at the fingers.
Also, with knuckle extensions it seems easier to achieve the "invisible" gliss -- slow enough that one can find the pitch -- fast enough that the listener doesn't notice it. Again, with fingers extended, a little motion of the hand is amplified at the fingertips -- thus, one must play "carefully" (i.e., introducing tension) to hit the notes. With knuckles only, one can fluidly move from one note to the next without "fighting" the control issue.
~~ tension and bio-feedback ~~
Tension really shows up when playing the Theremin. Fortunately, the Theremin provides bio-feedback on the tension issue! The easiest way I have found to reduce tension is to LISTEN to what I am playing and to consciously play so that it SOUNDS relaxed! If your music flows -- if it sounds relaxed, then you are probably playing relaxed!
Of course, tension is ok if you are looking for a declamatory effect in the music -- Lydia Kavina seems able to turn it on and off as the music demands it. (Sometimes her playing is DEFIANT! Then she'll turn around and melt your heart!)
Unwanted tension will make your music sound forced when you want it to sound fluid. I have found, if my performance sounds forced -- that I am usually trying too hard to mask the glisses between notes. The antidote is to slow down a bit.
In fact, slow practice on the Theremin is the best way to learn to play rapidly (same as all instruments). Practice playing without stress at slow tempi and as you speed up the relaxation will carry into your playing. If you feel tension, take a tempo that is slow enough that you can relax.
If all else fails and you are simply "stressed out", better to stop practicing, and spend the day/evening doing something relaxing. Come back to the Theremin when
