(Ger. ‘back positive’; Dutch rugpositief).
The little organ placed at the organist’s back, in the front of the gallery; the second main manual of all major organs from 1400 to 1700. In the smaller organs of most countries it was replaced by the Brustwerk, the Choir organ or the Swell, while in Italy there was only ever a handful of examples. The name has varied widely; for a discussion of terminology, see Chair organ.
Tonally, the Chair organ was always a contrast to the Great, firstly by being the first department to have its Mixture separated off from its Blockwerk into individual stops (Oude Kerk, Delft, 1548), later by having more single ranks on a slider chest, later still by having more delicate voicing and scaling (Werckmeister, Erweiterte und verbesserte Orgel-Probe, 2/1698); but the last characteristic had long been known, judging by Arnaut’s reference to its ‘sweetness’ (dulcedo). In some areas of the Netherlands and Denmark it continued to be built into the 1870s, but early in the 18th century central German builders dispensed with the Rückpositiv, giving its solo, accompanimental, colouristic and contrasting functions to the Oberwerk. Despite the dangers of heavy mechanism, the Chair organ is still the most important secondary manual for all classical organ repertories.
PETER WILLIAMS