Their harmonies and disharmonies, their fusing and blending, is not controlled by any outer necessity, but by the inner agreement and disagreement of our free impulses.

And yet in this world of musical freedom, everything is completely controlled by esthetic necessities.

No sphere of practical life stands under such rigid rules as the realm of the composer.

However bold the musical genius may be he cannot emancipate himself from the iron rule that his work must show complete unity in itself.

All the separate prescriptions which the musical student has to learn are ultimately only the consequences of this central demand which music, the freest of the arts, shares with all the others.