Much of Bach's organ music was written during the earlier part of his career, culminating in the period he spent as court organist at Weimar. Among many well known compositions we may single out the Chromatic Fantasia & Fugue in D minor, BWV 903, the Dorian Toccata & Fugue in D minor, BWV 538, the Toccata, Adagio and Fugue, BWV 564, Fantasia & Fugue in G minor, BWV 542, Passacaglia & Fugue in C minor, BWV 582, Prelude & St. Anne Fugue, BWV 552, (in which the fugue theme resembles a well known English hymn), Toccata & Fugue in D minor, BWV 565, and the Toccata & Fugue in F, BWV 540. The Chorale Prelude is a composition for organ that consists of short variations on simple hymn tunes for all seasons of the church year. Better known melodies used include the Christmas In dulci jubilo, BWV 508, Puer natus in Bethlehem, BWV 603, the Holy Week Christ lag in Todesbanden, BWV 625, and Easter Christ ist erstanden, BWV 627, with the moving Durch Adam's Fall ist ganz verderbt, BWV 637, and the familiar Wachet auf, ruft uns die Stimme, BWV 645, and Nun danket alle Gott, BWV 657.