Demi-jeu

What it means

Demi-jeu literally means “half play” and in French organ practice designates a reduced registration: instead of the full organ, only some of the stops are drawn, so that a medium, moderate sound arises. The expression does not fix a particular combination but describes a step of volume and colour between a delicate single stop and the grand jeu or plein jeu. What exactly is drawn depends on the instrument and on the tradition in which it stands.

Musical use

French organ music works with a pronounced system of named registrations in which every type of movement has its tone colour. Within this system, demi-jeu marks the intermediate step and is called for where music is meant to seem neither festive nor chamber-like — for instance in accompanying sections, in interludes, or when a work is to grow gradually. Since organs differ greatly in their specification and the terminology is not used uniformly in history, the marking is to be read as a direction, not as a recipe. On some harmoniums and bellows instruments, a stop of the same name additionally designates a halving of the wind pressure; this usage is to be distinguished from the organ-specific one.

Performance practice

First get an overview of the available stops and their gradation of volume, and then decide which combination gives the medium step on this instrument. Write down the chosen registration so that it stays reproducible in rehearsal. Check the sound from the nave or have someone listen, because the impression at the console is deceptive. With works with historical registration instructions, it is worth a look at the prefaces of the editions; they often contain concrete suggestions for instruments of different construction.

Remember that a medium registration does not simply mean half the number of stops: what counts is the tonal effect in the room, and a few strong stops can be louder than many quiet ones. Listen therefore in the nave and not at the console. With works with prescribed registrations, it is worth looking at sources and prefaces that name concrete combinations. Note down the solution found with stop names and pitch lengths in feet, so that it remains transferable to other instruments.