The same writer points out that instrumentalists in improvising their parts were prone to vie with each other in demonstrating their ability as contrapuntists, a perfectly comprehensible habit, which must have affected instrumental music in the sixteenth century as badly as the vagaries of coloratura singers affected operatic music in the eighteenth. Gerle’s book, incidentally, contained a number of German, Welsh, and French songs, and a fugue for four violins. Among other early books on the violin mention may be made of these: S. Virdung: _Musica getuscht_, 1511. Judenkönig: A truly artistic instruction * * * of learning upon the lute and violin, 1523. (Contains 25 numbers for violin and flute.) Agricola: _Musica Instrumentalis_, 1528. (Here the author refers to the vibrato as a device that ‘makes the playing more sweet.’) La Franco: _Scintille di Musica_, 1533. Silvestro Ganassi: _Regola Rubertina che insegna suon di Viola d’arco_, 1543. Ludovico Zacconi: _Prattica di Musica_, 1592 (Zacconi stated here that the compass of the violin was g-ciii). M. Prätorius: _Syntagma Musicum_, 1619. Touching upon the use of the violin in the sixteenth century there is extant a wealth of historical references. From one of these, for example, we gather that at a public festival in 1520 viols were used to accompany songs. We may assume their popularity in England from the fact that they were used in the family of Sir Thomas More (1530), an ardent music lover, and that during the reign of Edward VI the royal musical establishment increased the number of its viols to eight. Violins were used at public performances in Rouen in 1558; at a fête in Bayonne for dance music in 1565, and in a performance of a Mass at Verona in 1580. In the year 1572 Charles XI of France purchased violins from Cremona and a little later ordered the famous twenty-four violins from Andrea Amati. In 1579, at the marriage of the Duke of Joyeuse, violins were used to play for dances, and Montaigne in his _Journal_ (1580) refers to a marriage ceremony in Bavaria, where ‘as a newly married couple went out of church, the violinists accompanied them.’ From this passage of Montaigne we may infer that, in Germany at least, the popularity of violin music was not confined to the upper classes. It must be remembered, however, that the terms ‘viola,’ ‘violin,’ ‘viol,’ etc., were often applied indifferently to stringed instruments of various kinds, and in view of this inaccurate nomenclature historical references must be accepted with a certain amount of reserve.