Mouthing Off
Wayland Harman

Wayland Harman, instrument inventor, fine wood-worker, and JawHarpist, examines the essense of mouth cavity  instruments in this running series.

Playing the mouthbow

    The mouthbow is played in a similar manner to the trump. Both utilize variance in the mouth cavity to accent harmonics. With a mouthbow, a tunable string allows changes in the instrument’s fundamental pitch, while the trump is at a fixed pitch. Many mouthbow performances feature pitch changes of the string by flexing the bow; in fact this is the most audible of playing the mouthbow. The harmonics are typically too soft for an audience to hear. Nonetheless, these harmonics are quite apparent to the player and with careful mouthbow construction and very focused microphone techniques, can be made musically useful in a performance environment.

    Hold the mouthbow at about its center of gravity with your weaker hand, and with the string away from you. Place the end where it is most resonant up to slightly opened lips. Experiment to find where you get good tones. This arrangement leaves your dominant hand free to strike or pluck the string. A detailed description of each aspect will follow.

    The hand holding the bow can, depending on the instrument design, also serve as a string mute. I use my index finger to create a stop in the drone, which adds rhythmic interest. When the stop is released in perfect time with the string pluck, a harmonic is produced similar to that of a guitar. Finding a harmonic node along the string’s length may require moving the bow from its center of gravity. When this string harmonic is accurately reinforced by the resonance of the mouth cavity, a strong note can be sounded. This finger can also pluck the string, and will sound slightly different than the plucking or striking of the string close to the end.

    Plucking the string can be done many ways including: guitar or finger picks, bare fingers and fingernails, struck with a small baton (stick), bowed like a violin or by hitting the frame, such as happens if you rake a stick over a series of notches in the bow frame. In one ancient design, a small quill is placed on the string and the player forcefully blows on the reed followed by a moment of playing the string. This pattern then repeats. This is the only mouthbow I am aware of that uses airflow.

    My personal favorite is to strike the string with a wooden conductor’s baton (the fiberglass ones break up). It’s fairly easy to stay in rhythm and some fancy double and triple bounces can be done. The direction of the baton’s impact is a benefit on the style of bow I use as more energy is moving front to back, i.e. toward and away from my mouth. A guitar pick sends more energy side to side which isn’t as useful.

    I encourage you to try many ways of plucking, striking and coercing the string to life. Each has something unique and all are worth exploring. A current daydream of mine is to build a very large mouth bow, designed for team playing. Several players could strike and bow the string and 1 or more could play the harmonics.

    To say that the mouth performs the same movements as when playing a trump is not quite true but still a good starting point. The mouthbow requires very accurate resonance matches to produce good strong harmonics. Changes in overall mouth cavity size are more important than the shape. If the mouthbow wasn’t such a struggle to get any volume out of then this might not be so inherent in the playing. The wonderful vowel variations possible on the trump are much less prevalent with the mouthbow. I believe it is in the very nature of a vibrating reed to have a more complex vibrating pattern; thus more of a cloudy nature which allows vowels and some cheating out of notes which normally would not be found in the harmonic series of the trumps fundamental pitch. The advantage in this limitation, is the flutelike purity of the harmonics when you really nail one. Nothing else sounds like a mouthbow!

    Although typically unaided by airflow as with the trump, the mouthbow still has a long sustain time. The decay rate for a string is much longer than for a free reed. To use this sustain in performance requires extreme microphone placement. It is possible to play into a fairly hot SM57 on stage as long as the rest of the band holds way back to let you be heard. The audience will hear your strikes and plucks and a bit of a whistle from the harmonics. You will need to keep your mouth very close to the microphone, and will most likely find yourself relying on the extra punch of the strike; not the beautiful sustained harmonics.

    There is a solution, extreme but effective. Instead of mic-ing the area outside of the mouth (an area filled with non-harmonic sound such as the strings drone and the rest of the band and audience); try mic-ing the area inside the mouth. This is where the individual harmonics live.

    I have said regarding my mouthbow designs that; any sound, which doesn’t go into your mouth, is working against you. This microphone technique takes that approach a step further, by capturing the harmonics before they leave your mouth. It may be necessary to use a second microphone to pick up a little drone sound and mix it into the mouth mic.

    Experiments with both electrical and semi-mechanical methods of pulling the sounds from the corner of the mouth have been successful to a point. Obviously having a little microphone tucked into the corner of your mouth while playing these instruments is a bit inconvenient. My especially shaped funnel is not much better but uses a better quality microphone. In addition to the discomfort of the appliance, there is the problem of unwanted mouth sounds, saliva clicks and the tongue hitting the microphone. Some consideration and adjustments must be made in the playing to avoid these problems. The instrument will also need to be shifted from the center, over to the side to keep the string from contacting the appliance.

    OK, so it’s not perfect, however, I find the results are worth the trouble. Now the audience can hear why I am so fascinated by the mouthbow, even when the band is playing. The sustained whispers can be boosted to compete with an electric guitar. The mouthbow can carry the rhythm and the band can follow. It is such a thrill to know that the audience can hear me, now if I can just loose the appliance. Any dentists out there with a strong interest in microelectronics?