Technique
Technique lab
One angklung, isolated, with its strike pattern exposed. What you see is what the synthesis hears.
- dasar · 440.0 Hz · sounding
- oktaf · 880.0 Hz · sounding
- 2/2
One chain, not three pictures
1 · The technique becomes a train of strikes. Kurulung shakes the base tube and every reversal of direction is one strike, so 2–3 shakes per second gives 4–6 strikes. Centok is a single harder strike. Tengkep is kurulung with one tube held.
2 · Each strike excites the tube’s modal bank. A tube is not one frequency but several modes sounding together and decaying at their own rates. The list below is that model, and you can edit it.
Tube mode bank
This is the model itself, not a preview of it: one resonant mode per row — its multiple of the fundamental, its strength, and how long it takes to fall by 60 dB. Pitch and onset counts are settled by measurement; timbre cannot be, which is why this part is tuned by ear here.
3 · Every sounding tube is summed into the waveform. This is where tengkep acts: a held tube never enters the sum, so its modes are genuinely absent — not lowered, not filtered.
What is simplified: a shake has no predetermined length, so kurulung and tengkep are rendered here at six seconds and faded on release. Hold one longer than that and what you hear is an approximation.
2–3 Hz
Angklung akompanimen
On an angklung melodi, tengkep silences the octave tube, so you hear one pure note instead of the usual two. On a major angklung akompanimen it does something else: without tengkep four tubes sound a dominant seventh; hold one tube with the little finger and three remain, a major triad. The player’s little finger is a chord-quality switch.
Dominant seventh chord
4/4 tubes sounding
- 130.8 Hz · 0 cents · root
- 164.8 Hz · 400 cents · major third
- 196.0 Hz · 700 cents · perfect fifth
- 233.1 Hz · 1000 cents · minor seventh
These four tubes — root, third, fifth, seventh — are what make this a seventh chord. The name does not decide it; those four distances do.