Registration (organ)

Registration is the technique of choosing and combining the stops of a pipe organ in order to produce a particular sound.

For example, a stop labeled 22⁄3' sounds at the interval of a twelfth (one octave plus a fifth; or 3:1 ratio) above unison pitch.

Certain stops called mixtures contain multiple ranks of pipes sounding at consecutive octaves and fifths (and in some cases, thirds) above unison pitch.

A combination action is a system designed to store specific organ registrations to be recalled instantaneously by the player while they are playing.

Often, the toe studs will be labeled with dynamic markings reflecting the loudness of the registrations which result when they are pressed.

This system allows the organist to set the stops to a specific registration (very quiet, for example) and then suddenly change it for a short period of time (to very loud, for example) simply by pressing the appropriate toe stud.

This is especially helpful when playing the organ works of German romantic composers such as Max Reger and Franz Liszt.

Because the organ predates the advent of electricity, the entire system operates through mechanical and pneumatic means.

The combination action consists of six stop knobs, one for each division of the organ, connected to a system of pneumatics.

Using this system along with the pédales de combinaison, an organist (and an assistant or two) can prepare elaborate registrations in advance of their use during a performance.

In spite of its shortcomings (which are apparent only in light of present-day combination actions), it is an ingeniously designed system that was groundbreaking for its time.

Large setterboards consisting of a grid of switches were built inside the console or the organ case.

This process was quite time-consuming, and in most cases required the organist to leave his position at the console entirely to change even one stop on a piston.

Occasionally provision would be made for Pedal stops to be affected by manual pistons, allowing for a suitable bass.

This is especially useful in academic and concert settings, as it makes it unnecessary for organists to write down their registrations and reset the pistons every time they sit down at the organ.

In recent times, sequencers have become an integral part of combination actions, primarily on large organs.