Positive organ

A positive organ (also positiv organ, positif organ, portable organ, chair organ, or simply positive, positiv, positif, or chair) (from the Latin verb ponere, "to place") is a small, usually one-manual, pipe organ that is built to be more or less mobile. It was common in sacred and secular music between the 10th and the 18th centuries, in chapels and small churches, as a chamber organ and for the basso continuo in ensemble works. The smallest common kind of positive, hardly higher than the keyboard, is called chest or box organ and is especially popular nowadays for basso continuo work; positives for more independent use tend to be higher.

From the Middle Ages through Renaissance and Baroque the instrument came in many different forms, including processional and tabletop organs that have profited relatively less from the renewed popularity the type in general has enjoyed from the Orgelbewegung onwards.

Many positives, both of the box and 'cupboard' types, can be divided into upper and lower parts to be more easily moved. The lower part then usually contains the bellows, blower and/or treadle, and perhaps a few of the largest pipes. Wheels, casters or a custom-made hand truck are other aids to mobility, which have become vastly more common in modern times.

Positive organs typically exhibit few stops due to their small size and portable nature; a specification of 8′ stopped, 4′ flute and 2′ principal (diapason) is common. Somewhat larger positives may also have a 2-2/3′ and/or other mutation stop and/or a small mixture, and some have an 8′ reed stop (such as a regal). Still larger positives may have a 4′ principal or a second 8′ stop, the latter often treble-only. More complex examples feature a divided keyboard, which allows each stop to be activated separately in the treble and bass portions of the keyboard. This makes it possible to play a melody and an accompaniment simultaneously on different registrations. Most positives have just one manual keyboard and no pedals, but there are examples with a set of pedal pulldowns or even a pedal stop or two, as well as rarer ones with two manuals.

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