 A typical combo organ has one manual (keyboard), covering four or five octaves, though a few models had two manuals of three or four octaves.A number of different pitches and tone-colours ("voices") were featured, often using rocker-switches, tabs or drawbars to function as "stops" to select them.Although the sounds may bear such names as "flute", "string" or "horn", they are not intended to sound like their orchestral namesakes - the nomenclature is borrowed from pipe organ tradition.