The Well-Tempered Clavier (German: Das Wohltemperierte Klavier), BWV 846–893, is a collection of solo keyboard music composed by Johann Sebastian Bach. He gave the title to a book of preludes and fugues in all 24 major and minor keys, dated 1722, composed "for the profit and use of musical youth desirous of learning, and especially for the pastime of those already skilled in this study". Bach later compiled a second book of the same kind, dated 1742, with the title Twenty-four Preludes and Fugues. The two works are now considered to make up a single work, The Well-Tempered Clavier, or "the 48", and are referred to as The Well-Tempered Clavier, Book I and The Well-Tempered Clavier, Book II, respectively. This collection is generally regarded as being among the most influential works in the history of Western classical music. The first set was compiled in 1722 during Bach's appointment in Köthen; the second followed 20 years later in 1742 while he was in Leipzig. Both were widely circulated in manuscript, but printed copies were not made until 1801, by three publishers almost simultaneously in Bonn, Leipzig and Zurich. Bach's style went out of favour in the time around his death, and most music in the early Classical period had neither contrapuntal complexity nor a great variety of keys. But, with the maturing of the Classical style in the 1770s, the Well-Tempered Clavier began to influence the course of musical history, with Haydn and Mozart studying the work closely. Each set contains twenty-four pairs of preludes and fugues. The first pair is in C major, the second in C minor, the third in C-sharp major, the fourth in C-sharp minor, and so on. The rising chromatic pattern continues until every key has been represented, finishing with a B-minor fugue. WIKIPEDIA
VIDEO: Bach Well Tempered Clavier Book 1 Maurizio Pollini
