Arp Schnitger’s early modern examples of this instrument inspired a 20th-century “reform” movement that championed Baroque practices such as the use of high-pitched mixtures. A piece of music for this instrument begins with the three notes “G, high D, long B-flat” and has the common nickname “little.” The “Orpheus of Amsterdam,” (10[1])Jan Pieterszoon Sweelinck (10[1])(“yahn Peters-sown SWAY-link”), was renowned as a performer of this instrument. An 18th-century Büchlein (“BYOOKH-line”) of music for this instrument consists of chorale preludes. The Lübeck virtuoso Dieterich (10[1])Buxtehude’s (10[1])(“book-stuh-HOO-duh’s”) skill on this instrument prompted an arduous journey by a composer who later wrote a Passacaglia and Fugue in C minor for it. For 10 points, name this primary instrument of J. S. Bach, (-5[1])which usually contains multiple keyboard manuals and a pedalboard. (10[1])■END■