certainly the case that Österreich was participating in opera performances at the Theater am Hagenmarkt in Brunswick by at least 1708, when he was named in connection with a staging of Georg Caspar Schürmann's "Der erfreuten Ocker Schäfer eingestelltes Fest," though he was likely involved earlier than that. The opera was founded by Anthony Ulrich, Duke of Brunswick-Wolfenbüttel in 1690 and staged productions twice a year during the local fairs. Österreich continued to work in connection with the opera until at least 1721. In Brunswick Wolfenbüttel, Österreich came into contact with the modern musical currents of the age. In the late 17th century, the French style of Kapellmeister Johann Sigismund Kusser was the fashion. However, at the beginning of the 18th century, a dramatic shift took place when, in 1701, the Duke sent Schürmann to study in Italy to adapt to the new musical tastes. Österreich was not unaffected by these changes. He also changed his musical vocabulary drastically. Unfortunately, few works from this transitional period (1704-1719) survive, so the development of his style can only be partially reconstructed. In addition to his duties as singer, cantor, and singing instructor, Österreich also taught composition, passing on what he had learned from Johann Theile, above all regarding counterpoint. His most important student was Heinrich Bokemeyer who was Cantor at the princely Schule zu Wolfenbüttel and from 1739 was a member of Lorenz Christoph Mizler's Corresponding Society of Musical Sciences. How long Bokemeyer was Österreich's student is not known (the documents state "around 1706") but they developed a close friendship. In the 1720s, Österreich successively sold Bokemeyer the music collection, primarily church music, that he had established in Gottorf. Bokemeyer added to the collection with mainly secular works from contemporary composers. At least half of the collection survives today and is maintained by the Berlin State Library. It includes currently 1,839 titles, which are primarily scores. Most musicologists call it the "Bokemeyer Collection" though 1,702 of the works go back to the Gottorf collection, rendering the name somewhat misleading. It is written in various places that Österreich held the position of vice-Kapellmeister in Wolfenbüttel. However, this cannot be confirmed in surviving contemporary documents, as many archives of the time were lost or destroyed during the world wars. In any event, it appears that at the very least he held such a position in a de facto form, even if he was never