Introduction

The single pipe that sounds middle C from that rank will sound only if the stop for the rank is pulled AND the key middle C on the appropriate manual is depressed. In other words, when the key is depressed, a valve underneath the pipe opens, allowing air into the pipe ONLY IF the appropriate stop has been pulled.

The key action (mechanical, electric, or electro-pneumatic) can have some influence over the manner in which the pipe speaks. Pipes make sound by producing vibration in one of two ways: either a column of air vibrates (as in a toy whistle), or a reed vibrates (as in a clarinet).

Combinations of stops may be pulled by hand, or may be set into memory and recalled through the use of the combination action (including the thumb pistons, toe studs, set button, and multi-level memory).