We tend to think of Johann Mattheson (1681–1764) as a theorist first and foremost, and as a composer almost as an afterthought. To be sure, he competed in a world in Hamburg that at one time or another featured Reinhard Keiser, Georg Philipp Telemann, and George Frederick Handel; indeed, all of these were friends, sometimes rivals, and in one case, he and Handel even fought a duel over an opera, Cleopatra (Mattheson would have won, but a metal coat button deflected his sword, fortunately both for posterity and Handel). As a singer, he was well regarded, but by 1705 he had traded his performance chops for a real job as private secretary to the English ambassador.