The knobs on each side of the keyboards control which row of pipes, called ranks, are to be played. Each rank of pipes (usually 61 pipes) has a specific sound and pitch. The type of sound is indicated by the name, and the pitch is indicated by the number on each drawknob. The number 8 indicates that the rank of pipes will sound at the standard pitch, like a piano. The number 4 indicates the pitch will actually be an octave higher.
When a button, called a piston and located below each keyboard, is pressed a combination of drawknobs can be either pulled out or pushed in. This is called "combination action". These pistons are programmed by the organist, enabling him or her to quickly change registrations.
The organist has 256 different levels of memory available to program the combination action. The console also has an instant transposer.