Another inheritance from Buxtehude is the prelude and fugue in G minor;[72] especially the prelude, with its wealth of harmonies suddenly broken off, hardly to be employed again; the fugue, with the repeated notes in its subject. An advance over all the fugues of which we have thus far spoken, this one is notable for its strict maintenance of four-part polyphony; the facility and the spirit which we observe in the counterpoint, especially at the entrances of the subject, and the flexibility of the imitations, indicate the presence of a new wealth of resource, and a surety of technique which is master of itself. [Footnote 72: P. iii, 5; B.-G. xv, p. 112.] We must also include in the product of this period a set of eight preludes and fugues,[73] which, although very simple, are already the work of a fine hand. They are undoubtedly compositions which Bach destined for his pupils. [Footnote 73: P. viii, 5. These works are part of the collection of G. Pölchau, a well-known musician of Hamburg in the last century.] Bach is now about to cast himself free from the restrictions placed about him by the study of his first masters; finally in possession of all their resources, he will acquire those of others, enlarging his field of vision, already marvelously well-prepared by his earlier labors to make room for the results of his search after new conquests. II During Bach's first years in Weimar a new factor enters into his evolution, or rather forces itself upon it, quite without seeking on his part; it is simply the result of the experience gained in the fulfilment of his new duties. Ever since this epoch Weimar has been distinguished among the German courts by a more refined culture, a taste for art which up to the present time has never diminished. In this instance the impetus did not emanate from the reigning prince. Wilhelm Ernst was a man of education, it is true, and in his service were good artists; but, absorbed in a solitary life[74] of exceeding piety, and occupied with good works, the duke entrusted to his nephew, Johann Ernst,[75] the duty of encouraging his musicians. Johann Ernst was skilled in music, playing the harpsichord and the violin; he had even studied the elements of composition with Walther;[76] music was made to cater to his sickly constitution, especially the Italian chamber music, for solo instruments and orchestra, whose subtle charm was well suited to this invalid; for he himself could take part in its performance.