Related to J.S. Bach, his almost exact contemporary, on his mother's side, Johann Gottfried Walther was an important German organist and composer. His first organ lessons were in Erfurt with Johann Bernhard Bach, and he quickly became an able child singer. When he was 18 he landed his first organ post, at Erfurt's Thomaskirche. After a flirtation with philosophy and law at the local university, Walther turned all his attention to music, becoming especially interested in music theory. He began touring Germany on a regular basis, and in his travels he met the important theorist Andreas Werckmeister, becoming one of his protégés, if usually by long distance. In 1707 he obtained his first and only "real" adult job, organist at Weimar's Stadkirche; there he remained for the rest of his life, another four decades. He also served as music teacher to Prince Johann Ernst in Weimar, to whom he would dedicate his 1708 treatise, Praecepta der musicalischen Composition. In 1721, he added the duty of heading the ducal orchestra. J.S. Bach came to the ducal court in 1708, and the cousins struck up a close friendship, which benefited Walther artistically as much as, though perhaps not more than, his relationship with Werckmeister had. Walther was an omnivorous collector of information on music and theory, which led to the publication in 1732 of his Musicalisches Lexicon, Germany's first major music dictionary, incorporating entries on both biography and terminology. His career stalled out, though, and Walther never rose through the Weimar musical system, much to his bitter regret. The Lexicon is Walther's greatest legacy, but he also left a solid body of compositions, mostly organ pieces (only one vocal work out of nearly 100 has survived). Most of the organ works are chorale-based: individual chorales, chorale partitas, and chorale fugues, most of them comparable in quality and brilliance of keyboard technique to Bach. Early in his career, Walther also produced the Praecepta der musicalischen Composition, a useful music-theory compendium cribbed from seventeenth century treatises; the second part is a valuable survey of German Baroque composition procedures.