Burney says of the Mannheim orchestra, “This is the birthplace of the crescendo and diminuendo”; and the philosopher, Schubart, is recorded as saying of the orchestra under Cannabich, “Here the forte is a thunder, the crescendo a cataract, the diminuendo a crystal stream babbling away into the far distance, the piano a breeze of spring.” As for the symphonies of Cannabich, they do not seem to represent any advance toward the establishment of modern form. From the preceding account it will be seen that the external form of the symphony was already partly determined when Haydn began his artistic career. Under his treatment and that of his successors its growth, in all respects, was marvellous. Haydn is justly called the real creator of the modern symphony and string quartet. He enlarged the works, as a whole, extended the separate movements in their larger and smaller divisions, and developed the so-called art of free thematic treatment. He first gave musical clearness, order and variety to the form, and adapted it to the expression of the multitude of different phases of musical thought. The stricter thematic imitations of the older masters gave way to that free thematic play which has been an element of all concert music since his time. In Haydn’s development of this principle we recognize a power of invention and fertility of imagination only equalled by few others. The originality of Haydn cannot be over-estimated. He discovered a new world in music. An infinite variety of musical effect was produced by his new art of motive-building. Haydn also laid the foundation of modern orchestration. He understood, as no one before his day, the true scope of the combined stringed instruments. In his string quartets, even more than his symphonies, his mastery of the technical effects of the solo strings is most complete; for though the possibilities of tone-color are greater with the full orchestra, yet in Haydn’s quartets there is a wealth of musical expression and a certain charm of style which place them beside those of Mozart and Beethoven.