Fantasie und Fuge a-Moll, BWV 904

Bach composed this piece around 1725 at the beginning of his Leipzig years. The character of the "Fantasie" is serious and grave; even in the interludes a contemplative mood prevails. Its concerto form is strictly symmetrical: the main theme appears four times with three interludes between. The four-part double "Fugue" exemplifies Bach's superior contrapuntal craftsmanship as he combines two contrasting themes---one that's diatonic, rhythmic and agile, and another that consists of a descending chromatic line.