Johann Sebastian Bach - booksnow.scholarsportal.info

232 JOHANN SEBASTIAN BACH.Silbermann's pianofortes, and Bach himself had had someshare in perfecting these instruments.*^ The king hadseveral, and Bach was required to try them, and improviseupon them. On the following day Bach played the organin the Church of the Holy Ghost, at Potsdam, before acrowded audience ; but the king does not seem to have beenpresent. However, he commanded his presence at thechateau again inthe evening, and desired to hear him playa six-part fugue, that he might learn to what a pitch theart of polyphonic treatment could be carried ; Bach was tochoose his own theme, since every subject is not fitted fortreatment in so many parts, and he won the king's completeapproval by his performance.From Potsdam he also went to Berlin, and visited theopera-house built there in 1741-3 by Knobelsdorf. Nothingwas then being played there, however. For regular performancesonly Mondays and Fridays in December andJanuary were appointed, and besides these March 27, asbeing the Queen Dowager's birthday.*'^ But Bach wasinterested in any place dedicated to musical purposes. Itseems almost fabulous when the historian of this wonderfulman is obliged to mention one more of his many gifts ; but,it is nevertheless true that Bach's keen judgment hadpenetrated the mysteries of the conditions of buildingwhich were favourable to acoustics ; he detected everythingthat was advantageous or detrimental to musical effects inthe opera-house at Berlin, and, without hearing a note ofmusic in it, he saw at a glance all that others had learnedby experience. He also pointed out to his companions, inthe dining-room attached to the opera-house, an acousticphenomenon which, as he supposed, the architect had probablynot intended to produce. The form of the archesbetrayed the secret to him. When a speaker stood in one412 See Vol. II., p. 46.**ä See Marpurg, Hist. Krit. Beyträge. I., p. 75. Brachvogel relates, in hisGeschichte des Königl. Theaters zu Berlin (Berlin, Janke, 1877), Vol. I.,p. 12g, that Bach played at a State Concert with Signora Astrua ; but, in pointof fact, Astrua did not appear till August, 1747, in a pastoral performed atCharlottenburg. See Marpurg, op. cit., p. 82