It was through Froberger and Kerl that Bach became acquainted with Frescobaldi's works, and the Italian school; the sonata form was revealed to him by the French "suites" played by the orchestra of the ducal court at Celle, an organization which greatly interested him; but the greatest influence upon his youth was exercised by Buxtehude. It was from him that Bach learned in their integrity the old German traditions. When, at Hamburg, the aged Reinken heard Bach improvise for more than a half-hour upon the chorale _An Wasserflüssen Babylons_, he cried out, embracing him, "I thought that this art were dead; but I see that in you it still lives."[1] [Footnote 1: "_Ich dachte, diese Kunst wäre ausgestorben; ich sehe aber, dass sie in Ihnen noch lebt._"] These traditions he handed down later to his two oldest sons, Wilhelm Friedemann and Carl Philipp Emanuel--two musicians whose merit is universally recognized,--and to a whole galaxy of brilliant pupils: JOHANNES CASPAR VOGLER, a musician whom Mattheson considered more able than Bach himself. Vogler was organist at Weimar. Some preludes of his are published and written in the form of chorales for two manuals and pedal. HOMILIUS, of Dresden, a composer of church music. TRANSCHEL, of Dresden, a distinguished clavecinist. GOLDBERG, of Königsberg, composer of pieces called "_Bagatelles pour dames_," which no one could play, such was their difficulty. (He frequently found amusement in playing music of every variety from the inverted score.) KREBS, organist at Altenburg; not only a performer of the first rank, but a prolific composer. For nine years he enjoyed the invaluable supervision of Bach. ALTNIKOL, organist at Naumburg; Bach's son-in-law. AGRICOLA, composer to the King of Prussia, known through his theoretical works. MÜTHEL, of Riga. KIRNBERGER, court musician at Berlin. "He loved his art with a fervor at once enthusiastic and sincere," says Forkel. "Not only has he informed us in detail as to Bach's methods of teaching composition, but the musical world is still his debtor for the first logical system of harmony, founded upon the works of his master. The first of these sources of information is his book, _Die Kunst des reinen Satzes_; the second, _Grundsätze zum Gebrauch der Harmonie_. He furthered the interests of musical art by other treatises as well as by his compositions. Particularly charming are his works for the clavecin. Princess Amelia of Prussia was one of his pupils." KITTEL, organist at Erfurt. He was the only one of Bach's pupils still living at the time Forkel, himself an organist and the director of music at the University of Göttingen, wrote his _Ueber J.S. Bach's Leben, Kunst und Kunstwerke_ (Leipzig, 1802). [The Life, Art, and Works of J.S. Bach.]