Acoustics, Instruments and Accompanying Artists
This domain tests the physics behind the sound, the instruments that carry the music, and the accompanists a candidate should be able to name.
Sound and shruti
Sound is a longitudinal wave; frequency gives pitch, amplitude gives loudness, and the harmonic spectrum gives timbre. Hindustani theory divides the octave into 22 shrutis. The harmonium is equal-tempered, while voice and tanpura work from just intonation around Sa.
The drone
The tanpura has four strings, usually tuned Pa-Sa-Sa-Sa or Ma-Sa-Sa-Sa, with the jawari bridge shaping the overtones. It supplies the reference Sa and a continuous harmonic bed; without it, pitch drifts.
The tabla
The right drum, the dayan, is tuned to Sa or Pa by adjusting the gatta and syahi; the left, the bayan, gives the bass and is bent in pitch by the heel. Bols such as dha, dhin, na, tin and ge build the theka.
Harmonium and sarangi
The harmonium is the standard melodic accompaniment, tempered and easy to follow, but it cannot produce meend cleanly. The sarangi, bowed and fretless, can imitate vocal meend closely.
Accompanists
Tabla: Ahmed Jan Thirakwa, Kishan Maharaj, Suresh Talwalkar. Sarangi: Bundu Khan, Ram Narayan, Sultan Khan. Harmonium: Appa Jalgaonkar, Tulsidas Borkar.
Worked example
A singer's Sa feels unstable at the top of the antara. Check the tanpura first: if its Pa string has drifted or the jawari is dull, the reference itself is false. Reasoning: diagnose the drone before blaming the voice.
Traps
Saying the tanpura has three strings; confusing dayan with bayan; claiming the harmonium produces meend like a sarangi; naming an instrumentalist under the wrong instrument.