And then, though less fecund an inventor than Liszt, less rich and large a temperament than Berlioz, Strauss was better able than either of his masters to organize his material on difficult and original lines, and find musical forms representative of his programs. Because of their labors, he was born freer of the classical traditions than they had been, and was able to make music plot more exactly the curves of his concepts, to submit the older forms, such as the rondo and the theme and variations, more perfectly to his purpose. Compositions of the sort of "Till Eulenspiegel," "Tod und Verklaerung" and "Ein Heldenleben," solidly made and yet both narrative and dramatic, place the symphonic poem in the category of legitimate musical forms. The themes of "Till" grow out of each other quite as do the themes of a Beethoven symphony or of "Tristan" or of "Parsifal." Indeed, Strauss has done for the symphonic poem something of what Wagner did for the opera. And not an overwhelming number of classical symphonies contain music more eloquent than, say, the "sunrise" in "Also Sprach Zarathustra," or the final variation of "Don Quixote" with its piercing, shattering trumpets of defeat, or the terrifying opening passage of "Tod und Verklaerung." For Strauss was able to unloose his verve and fantasy completely in the construction of his edifices. His orchestra moves in strangest and most unconventional curves, shoots with the violence of an exploding firearm, ambles like a palfrey, swoops like a bird. There are few who, at a first hearing of a Strauss poem, do not feel as though some wild and troubling and panic presence had leaned over the concert hall and bedeviled the orchestra. For, in his hands, it is no longer the familiar and terrorless thing it once had been, a thing about whose behavior one can be certain. It has become a formidable engine of steel and gold, vibrant with mad and unexpected things. Patterns leap and tumble out of it. Violin music launches swiftly into space, trumpets run scales, the tempi move with the velocity of express trains. It has become a giant, terrible bird, the great auk of music, that seizes you in its talons and spirals into the empyrean.