Aspects of Organ Building

 In instrument building, technical innovations and improved craft techniques of the fourteenth and fifteenth centuries made  ever larger organs with expanded tonal potential possible.[6] In his Spiegel der Orgelmacher und Organisten of 1511, Arnolt Schlick drew a preliminary summary of these developments. The older Blockwerk, in which all the pipes sounded together, was gradually broken up, though often not fully, for example where an undifferentiated “Hintersatz” remained. This produced instruments that could have differentiated sound registrations in the modern sense.

Besides the main division (Hauptwerk), fifteenth-century organs often already had a Rückpositiv, and more rarely a further division played from a third manual. From around 1400, keys in the modern sense existed, replacing the stiff, sluggish older sliders. In the fifteenth century the pedal occasionally gained independence, although for a long time it continued to be built as a downward extension of the manual compass.[7]  The wind supply, too, was placed on new technical foundations. This came through better protection of the bellows, well-sealed windchests, and a shift from spring-chests to registrable slider-chests. Finally, over the course of the fifteenth century, meantone temperament became established, making possible an adequate rendering of newer vocal compositions. The impression made by the new stops, which imitated wind instruments, is attested by a traveling eyewitness of the time. In 1517/18 he heard the new organ of St Jakob’s church in Innsbruck and marveled at its “perfettissime voci” (perfect voices).[8]