"Beginning with Beethoven, however, composers began to exhibit great freedom in the application of Sonata-Form."

“The sensational style of Prometheus is augmented by the use of a color machine which flashes upon a screen hues supposed to supplement the various moods of the music.  How many of these experiments will be incorporated into the accepted idiom of music, time alone will tell; but they prove conclusively that modern music is thoroughly awake and is proving true to that spirit of freedom which is the breath of its being.”

“Walter Raymond Spalding at ancestry.com.”

“Finally, Beethoven's career coincided with momentous changes and upheavals in the social, political and artistic world.  He is the embodiment of that spirit of individualism, of human freedom and self-respect which found its expression in the French Revolution, in our American War of Independence and in the entire alteration of social standards.  Beethoven at all costs resolved to be himself.  With him music ceases to be a mere "concourse of sweet sounds"; it must always bring some message to the brooding human soul, and be something more than a skilful example of abstract ingenuity.  These personal tendencies of Beethoven were fostered by the spirit of the times, and his music became in turn a vital expression of revolt against existing conditions and of passionate aspiration towards something better.”

“It speaks to our feelings and imaginations, as it were by suggestion; reaching for this very reason depths of our being quite beyond the power of mere words.”

“Thus a very etherial, magical quality of tone is produced, especially in the upper ranges of the instrument.”

“The Development, beginning in measure 132, is a striking example of how difficult it was—even for an exponent of freedom in musical expression like Schumann—to break loose from the shackles of arbitrary form.”