Reinhard Keiser (9 January 1674 – 12 September 1739) was a German opera composer based in Hamburg. He wrote over a hundred operas. Johann Adolf Scheibe (writing in 1745) considered him an equal to Johann Kuhnau, George Frideric Handel and Georg Philipp Telemann, but his work was largely forgotten for many decades. Biography Keiser was born in Teuchern (in present-day Saxony-Anhalt), son of the organist and teacher Gottfried Keiser (born about 1650), and educated by other organists in the town and then from age eleven at the Thomasschule in Leipzig, where his teachers included Johann Schelle and Johann Kuhnau, direct predecessors of Johann Sebastian Bach. In 1694, he became court-composer to the duke of Brunswick-Wolfenbüttel, though he had probably come to the court already as early as 1692 to study its renowned operas, which had been going on since 1691, when the city had built a 1,200-seat opera house. Keiser put on his first opera Procris und Cephalus there and, the same year, his opera Basilius was put on at Hamburg and, as the musicologist Johann Mattheson noted, "received with great success and applause". This was a fruitful period for him – composing not only operas, but arias, duets, cantatas, sérénades, church music and big oratorios, background music – all for the city's use. About 1697 he settled permanently in Hamburg, and became the chief composer at the highly renowned Oper am Gänsemarkt (now rebuilt as the Hamburg State Opera) in Hamburg from 1697 to 1717; however he was actually first the director in 1702, and was not at various times from then to 1717, almost each time due to political instabilities. From 1703 to 1709, Keiser changed the opera house from being a public institution to a commercial venture with two to three performances a week, in contrast to the opera houses intended for the nobility. He helped transition opera from the mid-Baroque to the late-Baroque. He introduced a more varied type of aria into his operas, with more passive arias, and also faster arias being introduced into his bilingual and non-bilingual operas all by the 1703/04 season, Nebukadnezar, and Salomon. Early in 1704, when he was conducting the operas Nebukadnezar and Salomon in Hamburg, the season had to be unexpectedly concluded, for reasons most likely related to government affairs. He went to Brunswick, and afterward Weissenfels, to reconnect with areas in which he was previously active. He ended