=Eighteenth Century Clavier Composers=.—The Thirty Years’ War exercised a demoralizing influence upon music trades, and many excellent musicians were unable to have their compositions published in consequence. The result is, that comparatively few specimens of the works of the composers mentioned have come down to us in available form. Approaching the 18th century, we now come to a group of composers who represent the most brilliant epoch of early clavier work. Their productions, while retaining the dignity and complexity of the contrapuntal school, yet use its material with a freedom of modulation and of dissonant chords sufficient to express genuine emotional ideas through their medium. =Reinken and Buxtehude=.—The Hamburg organist =Johann Adam Reinken= (1623-1722), a native of Holland, wrote a number of clavier compositions, publishing in 1704, pieces for two violins and harpsichord. =Dietrich Buxtehude= (1637-1707), organist at St. Mary’s Church, Lübeck, from 1668, excelled in free style of writing for clavier. The latter gave a series of Sunday evening concerts at his church which gained renown through all the surrounding country; and J. S. Bach himself is said to have walked to these concerts, a distance of fifty miles. =Instrumental Polyphonic Forms=.—These men have been mentioned largely because their work made possible the results which Bach afterwards attained from an elaboration of what they had already accomplished. It was among such eminent German organists that the instrumental Fugue, the highest instrumental type of polyphonic music, took definite shape, consisting of an Exposition, in which the Subject, Answer and Countersubject were announced by the various voices; and a subsequent Development, in which, according to certain laws more or less strict, the material presented was carried through a variety of phases and brought finally to a triumphant close. Of other forms, like the Toccata and Canzona, the tendency came to be toward more freedom of treatment on the one hand, and an increasing definiteness and consistency on the other.