Pipe organ
There is another way of grouping the stops. Each stop will have a number underneath the name. The number may be 16, 8, 4, 2, 1 or even 2 2/3 or 1 3/5. If the number is 8 this is called an “eight foot stop”. This is the normal pitch: the note will sound as it is written, e.g. when playing Middle C the sound will be Middle C. A 4-foot stop will sound an octave higher than written, a 2-foot stop will be two octaves higher. A 16-foot stop will sound an octave lower than an 8-foot stop. 8 foot is therefore the normal pitch, and the others are added to it to make a larger, brighter sound. 16 foot stops are normal in pedal parts.