But as the earlier German composers subjected the Volkslied to elaborate contrapuntal treatment, while on the one hand they added to its range and depth of expression, on the other hand they deprived it to some extent of its indescribable charm. Artistic music began to be divorced from the Volkslied, and with the advance of musical education the latter seemed to be falling into decay. But with the revival of German literature which dates from Lessing, there began a new development of national spirit among Germans, of which we have seen the culmination in our own time. One of the early symptoms was the introduction of the Volkslied element into poetry by Herder and Goethe. About the same time we find the same element appearing in the thematic treatment of symphonies, sonatas, and string quartets by Haydn and Mozart, especially in the adagios. In Mozart's songs there is a great development in dramatic treatment, as for example, in "Unglückliche Liebe." The nearest approach made by Mozart to the kind of song afterward developed by Schubert was probably in "Das Veilchen," the only one of his songs set to Goethe's words. As Mozart was pre-eminently a musical dramatist, so was Beethoven first and foremost a symphonist; and in his songs the most noticeable new feature is the enrichment of the harmonies and the profound increase of significance in the instrumental accompaniments. We see this in the magnificent "Adelaide," which, however, resembles an aria rather than a genuine Lied. In some parts of Beethoven's exquisite cycle, "An die ferne Geliebte," he comes nearer to the Schubertian form of song.