The first classification embodies three distinct groups. The first of these groups contains all of Wagner's earlier attempts including "Rienzi," which is modelled according to the French and Italian "historic" school. With the exception of "Eine Faust Ouvertüre" which belongs also to this category, only occasional indications of marked genius are to be found in these works. The second group includes "Der Fliegende Holländer," "Tannhäuser" and "Lohengrin." These display a radical change in style, form and treatment, pronounced originality, continuity of music and a fusion of recitative and aria. The topics chosen for dramatization treat of German myths, mediæval legends, and chivalrous ideals. Indications of the _Leit-motiv_ principle, though used in an unobtrusive manner, are in evidence. The musical forms are not yet influenced by the profundity of thought and reflection that characterizes the works belonging to the third group. The third and last group includes "Tristan und Isolde," "Die Meistersinger von Nürnberg," "Der Ring des Nibelungen," and "Parsifal." The complete fulfilment of Wagner's philosophical theories are here exposed. Wealth of harmony, characteristic rhythm and intensity of expression are combined with poetic reasoning, depth of thought and vivid dramatization. The centre of gravity, so to speak, is transferred to the orchestra. _Sprech-singen_ is emphasized, whereas the _Leit-motiv_ principle reaches its full development. V. The second classification, relating to differentiated style of orchestration, is popularly divided into three groups, but a division into four groups would seem more appropriate to the present writer. Wagner's earliest orchestral attempts need not be taken into consideration, and so the first group may include only "Rienzi," "Der Fliegende Holländer" and "Tannhäuser." The scores of these works do not display radical departure from contemporary methods excepting in polyphonic treatment and individualistic coloring. The instruments of wood are as yet represented only in pairs, although already a cor anglais and a bass-clarinet are regularly employed. The addition of a second piccolo flute, a second English horn and a third bassoon is but exceptional. The numerical distribution of strings and the constituency of the brass are normal. Entirely new tendencies are discovered in "Lohengrin" and "Tristan und Isolde" which comprise the second group, since each wood-wind family is now represented by three instruments. The number of strings are augmented so as to balance the wood-wind, as well as in consequence of their own frequent subdivision; but the brass is the same as in Group I. The magnitude of the Nibelungen Tetralogy gave rise to the adaptation of the exceptional third group. The augmentation affects both the wood and the brass. The wood-winds are divided into families of four each, and the same principle is applied to the brass. Strings, harps and battery are augmented in proportion.