THE ORGAN

This is a keyboard instrument with wooden and metal pipes set in vibration by wind blown by bellows.

The greater (or smaller) the number of ranks of pipes of different materials and different dimensions an organ has, the greater (or smaller) the choice of stops by means of which the organist can change the tone, dynamic and range of the instrument. The mechanism by which the organist gets this or that rank to sound, drawing out a small piece of wood, is called a stop (registre).

The range of the instrument is not fixed. It depends on its size, normally determined by the length in feet of its largest pipe giving the lowest note on the keyboard. Thus one speaks of a 32-foot organ, or a 16-foot, or 8-foot, or 4-foot organ. If an instrument possesses the lowest rank, called 32-foot open flute, as well as the 16-foot open flute, the 8-foot open flute, the 4-foot prestant or open flute, and the doublette which sounds an octave higher than that, it has an immense range of eight octaves. The 32-foot range is from C″ up to c′, the 16-foot from C′ up to c″, the 8-foot from C up to c‴, the prestant or 4-foot from c up to c‴′, and the doublette from C′ up to c‴″, all these being chromatic. These five ranks thus have four octaves each, although many of those we mention below have only three or even two.