Strangers often asked Bach to play to them between the hours of divine service. On those occasions he was wont to select and treat a theme in various ways, making it the subject of each extemporisation even if he continued playing for two hours. As a beginning he played a Prelude and Fugue on the Great Organ. Then he developed it with solo stops in a Trio or Quartet. A Hymn-tune followed, whose melody he interrupted in the subtlest fashion with fragments of the theme in three or four parts. Last came a Fugue, with full Organ, in which he treated the subject alone or in association with one or more accessory themes. Here we have the art which old Reinken of Hamburg considered to be lost, but which, as he afterwards found, not only survived but attained its greatest perfection in Bach. Bach’s pre-eminent position and his high reputation often caused him to be invited to examine candidates for vacant organistships, and to report on new Organs. In both cases he acted so conscientiously and impartially that he generally made enemies. Scheibe, late Director of Music at the Danish Court, who as a young man was examined by Bach on such an occasion, was so incensed by Bach’s unfavourable verdict that he afterwards avenged himself in his “Critical Musician” by violently attacking his examiner.(135) In his examination of Organs Bach equally exposed himself to trouble. He could as little prevail on himself to praise a bad instrument as to recommend a bad organist. He was, therefore, severe, though always fair, in the tests he applied, and as he was thoroughly acquainted with the construction of the instrument it was hopeless to attempt to deceive him. First of all he drew out all the stops, to hear the Full Organ. He used to say jokingly, that he wanted to find out whether the instrument had good lungs! Then he gave every part of it a most searching test. But his sense of fairness was so strong that, if he found the work really well done, and the builder’s remuneration too small, so that he was likely to be a loser, Bach endeavoured, and often successfully, to procure for him an adequate addition to the purchase price. When the examination was over, especially if the instrument pleased him, Bach liked to exhibit his splendid talent, both for his own pleasure and the gratification of those who were present. Such demonstrations of his powers invariably invited the verdict, that he was conclusively “the prince of Clavier and Organ players,” a title which Sorge, the late highly-esteemed organist at Lobenstein,(136) once gave him in a dedicatory Preface. CHAPTER V. BACH THE COMPOSER