Well, suppose we use our brains. We see things solid. Solidities are important to us in nature. In solidities, there are measures that greatly affect us. There are rhythms in the ins and outs of form. Music, the forest and to many the most impressive of arts deals in measures which seem to go in every direction. They combine, they move together, they deflect and they oppose. Music is a structure of highly mathematical measures. According to the selection and relative value of these measures the music is great or small in its effect on us.