Contra octave

Below the great octave

In the older German system the octaves are counted upwards from the small c with strokes and downwards with names: the great octave carries capital letters, C to B, below it follows the contra octave with a subscript 1, then the sub-contra octave with 2. In the scientific count used in this glossary, contra C is “C1”, the great C is “C2”, and middle C “C4”. Each octave downwards halves the frequency, which is why C₁ with 32.7 Hz has exactly half as many vibrations as the great C with 65.4 Hz.

Frequencies

The table gives the seven notes of the contra octave. The values follow from the standard pitch A4 = 440 Hz and the equal division described on the page Standard pitch. For comparison: the lower limit of hearing is at about 20 Hz, so the notes of this octave still lie in the audible range, but near its lower end. Small loudspeakers can hardly reproduce them; you then hear mainly the overtones.

Where you play it

On the organ contra C sounds when you press the lowest key C on a 16-foot stop: the pipe is about five metres long. The 32-foot stop goes an octave lower into the sub-contra octave. The piano with its 88 keys reaches down to A0, the sub-contra A (A₂ in the older system); contra C is the fourth key from the bottom. On the double bass and the electric bass the lowest open string, E1 = 41.2 Hz, lies in the contra octave.

Common mistakes

• Confusing the number with the scientific octave number: contra C with subscript 1 is C1; here both numbers agree. For the upper octaves, written with strokes above, the scientific number is by contrast three larger.
• Equating the notation of the double bass with the sound: it sounds an octave lower than notated.
• Expecting too much of small loudspeakers: below about 100 Hz they hardly reproduce anything.