Why a jew’s harp should not ‘buzz’
One can often hear from beginners choosing a jew’s harp a wish concerning the instrument properties – it should ‘buzz’, or ‘get agitated’ only by breath, in other words, produce droning sounds without plucking the tongue with the hand. Sometimes this wish is the main or even the only one... This material will clearly show how and why ‘buzzing’ deteriorate the acoustic properties of a jew’s harp. It is worthwhile mentioning at once that a normal jew’s harp just does not need to buzz; for this method of sound production and play there are wind instruments including the nearest relatives of jew’s harps, mouth harps.
Why the jew’s harp buzz?
Buzzing is enabled by one certain feature of the instrument structure: its tongue must be bent away from the frame plane. If it is located strictly parallel to the frame, right between the decks edges, one cannot agitate it even by strongest breath.
Why jew’s harp with a bent tongue, a buzzing one, is worse than a straight one?
When the tongue is bent, the center line of oscillation is displaced, and this causes a number of negative effects, as follows:
- Sound loudness and duration after a single stroke (fade-out time) are decreased Sound loudness depends on the speed of tongue movement against the frame edges. The tongue tip moves along the arc pathway with a speed that is maximum in the middle and minimum at the ends of the arc; so, in case the deck edges are located against the tongue middle line, the tongue travels over them with maximum speed, as the farther it goes away from them, the lower the speed and the quieter the sound. Also, in this case the fade out time of the sound is even shorter, as tongue stroke length decreases. The extreme case is when the tongue is bent so much that even in the end of its stroke it does not reach the frame plane. An exaggerated example: let’s assume the tongue is bent 90 degrees, then there will be no sound at all. And if we suppose also an exaggerated pluck of a huge force, after which the tongue deflects to 90 degrees for the first time and reaches the decks, the second stroke will be totally ineffective.
- The timbre becomes dual, and is no more smooth The tongue moves over the decks in two directions, and in case its state of rest is within the frame plane, moving into both sides takes one and the same time, and the force of each air wave generated is the same, this mode generates smooth, classical jew’s harp sound. In case the tongue is displaced, the oscillations are divided into two – even and odd ones; they come one by one with different forces. Also, only in the middle line the tongue is straight and travels over the deck edges with all its blade length at one time. In all other positions the tongue is bent, and the bigger the bend angle, the more curved the tongue line, so the sound gets smeared time-wise and frequency-wise. As a result, an unmusical buzzing appears. And most important negative result - many of gentle overtones are gone away, hided by buzzing.
Experiment
Loading the player for nobuzz-neutral-sound.mp3...
It is no use to blow into it, as it should be. Loading the player for nobuzz-neutral-buzz.mp3...
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Loading the player for nobuzz-deflected-sound.mp3...
Hurray, it buzzing! Loading the player for nobuzz-deflected-buzz.mp3...
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The timbre is split, it is very hard to emphasize overtones, the sound fades away actually right away.
It is also possible to buzz with a right jew’s harp!
It should be done as close to the tongue attachment point as possible, with your nail; then the oscillations will be minimally damped.