Acoustics and Instruments
The physics you must state correctly
- Pitch corresponds to frequency; loudness to amplitude; timbre to the harmonic content of the waveform.
- Sound travels about 343 metres per second in air, faster in water and much faster in steel.
- Interval ratios: octave 2:1, perfect fifth 3:2, perfect fourth 4:3. Concert A is 440 Hz. Carnatic performers usually tune Sa to C or C sharp.
Instruments
- Saraswati veena: 24 frets, four melody strings and three drone strings.
- Violin: adopted into Carnatic music in the early nineteenth century by Baluswami Dikshitar; unfretted, so gamakas are made by the finger.
- Flute: bamboo, eight holes, pitch fixed by the instrument's length.
- Mridangam: barrel drum of jackfruit wood, two heads with black tuning paste.
- Ghatam: clay pot with a definite pitch set by size and wall thickness. Kanjira: lizard-skin frame drum.
- Tambura: four strings tuned Pa, Sa, Sa, Sa, giving the drone.
- Nagaswaram: double-reed temple instrument, played with the tavil. Chitravina: many strings over two or three bridges.
Worked example
A tambura's Sa string is tuned to 240 Hz. Reasoning: the Pa string must be a perfect fifth above, so 240 x 3/2 = 360 Hz, and the tara Sa sounds at 240 x 2 = 480 Hz. A flute whose Sa is 256 Hz cannot join this drone without retuning, because the mismatch produces audible beats.
Traps that cost marks
- Saying frequency determines loudness.
- Claiming the ghatam has no definite pitch; its pitch is real and is adjusted by the maker.
- Describing the violin as an Indian invention rather than an imported instrument.
- Forgetting that the tambura's fifth string tuning is not four identical strings.