How to Play a Theremin

The theremin works without the slightest touch. It's got two antennae -- one horizontal and one vertical -- each of which has an electromagnetic field surrounding it. When you move your hand in front of the instrument, you create interference. If you've ever tried to improve a fuzzy picture on an analog television with rabbit-ear antennae, you've created a similar effect to the principle behind the theremin [source: Levenson]. Our hands and bodies contain a natural capacitance (stored electric charge) that affects electromagnetic fields.

When your hands alter the theremin's surrounding electromagnetic fields, the interference causes an audible sound. The electromagnetic field around the horizontal antenna controls the volume of that sound, and the vertical one controls the pitch.

For the purposes of our hypothetical example, pretend you're a right-handed thereminist, with the horizontal antenna on your left and the vertical on your right. (Left-handed thereminists can have a special version made with the setup reversed, or they can simply turn the instrument around and approach it from the opposite side.) Using your right hand, you can change pitch by moving it at shoulder-height back and forth between your body and the antenna. The closer your hand gets to the antenna, the higher the pitch. Pulling your hand away lowers the pitch -- the lowest pitch occurs about 2 feet (0.6 meters) away from the antenna.

Of course, while you're playing the theremin, you've got to control the volume in conjunction with the pitch. To do this, move your hand up and down (not back and forth, like you do to control the pitch) over the horizontal antenna. The lowest volume starts as you hold your hand about an inch (2.5 centimeters) above the horizontal antenna. As you lift your hand up, the volume gets louder. As your hand rises about a foot (0.3 meters) from the antenna, you'll achieve the loudest volume.

We should note that these spans are approximate because volume and pitch depend on the individual instrument. This also means that the distance between the individual notes can vary. In some machines, you'll experience a delayed response between your hand movement over the horizontal antenna and the change in volume. Each player becomes familiar with his or her own instrument to know exactly how wide these spans are.

Obviously, playing a song with this quirky instrument takes coordination and practice. Next, we'll get some tips from the experts.

­Although it may take years of practice before you master the instrument, some believe the theremin is worth the time and effort. Lydia Kavina has played it since she was a young girl and has become one of the most famous thereminists. In fact, she studied under the master himself, Leon Theremin. She has some pointers for beginning thereminists.

Kavina suggests that you position your feet about 1 foot (0.3 meters) apart while playing. The distance between yourself and the instrument can depend on the individual range of that theremin. If the instrument spans four octaves or less, you can stand a foot to 16 inches (0.4 meters) away. A larger range might require you to stand even farther away, depending on your purposes. If you need to take advantage of the full range, you should feel free to change your body position during the performance [source: Mattis].

She also recommends tuning the instrument -- setting the lowest note with your right hand at your shoulder. To play in tune, always keep the melody in mind, and practice the song slowly at first [source: Mattis]. A seasoned thereminist doesn't constantly move his or her whole arm back and forth to control pitch; instead, he or she uses delicate finger movements. This often involves opening and closing the hand to achieve the right notes. However, many thereminists choose not to open the whole hand but instead keep the thumb and forefinger together. Likewise, the left hand's control of volume might involve movement of the whole arm or subtle wrist movements.

So what circumstances call for actually touching the instrument? Kavina explains that touching the vertical pitch antenna can create a birdlike trill sound for special effects, and lightly striking the horizontal volume antenna mimics a groaning sound in some theremins.

Clara Rockmore, another famous thereminist, advises that you stay conscious of all your body movements. If you get emotionally wrapped up in the music, you might tend to sway or move your head. These motions can alter the electromagnetic field and affect your music [source: Mattis].

Posture also comes into play if you want to avoid developing conditions such as tendonitis or carpal tunnel syndrome. Kavina advises a straight back as one good preventive measure. But you can also perform stretching exercises for your hands to stay in top performing shape.