By composing music a composer must create his own world in sound and rhythm. His work, therefore, is not a labor, it is a joy, a joy of the highest order. If the composer writes music because he is obliged to write something, that is not the thing to do. The composer should write when his heart feels like writing, when his heart is singing, when his soul is dancing, when his whole being is vibrating harmony. That is the time that he should write music.