It was a long time before these two means of organizing sound were used in combination. Until the seventeenth century metrical form was chiefly used, quite naturally, to define the gesticulatory part of musical material, the product of active emotion, while harmonic form gave coherence to the vocal part, the product of contemplative or religious emotion. Primitive dance either neglected pitch relationship entirely, as in that kind of savage music which uses only drums, tomtoms, clappers and such percussive instruments, or used only the simplest intervals like the fall of the fourth or the rise of the fifth. And in ecclesiastical Song, all through the Middle Ages, metrical regularity was not only not sought for--it was avoided. Even in the highly artistic song of the great choral epoch which culminated in Palestrina there was no rhythm. Phraseology depended entirely on the words. Composers avoided anything like an appearance of even sections, in sharp demarcation, balancing each other, such as we now demand. They liked rather to have their melodies cross and interlace like the strands in a basket, making a texture solid but inorganic. To them coherence was a matter merely of the individual voices; music held together like a rope rather than like a crystal. Indeed, any deeper harmonic unity was not feasible until they had gained more experience in tone relationship. But eventually the secular composers of the last half of the seventeenth century, among whom Arcangelo Corelli is a typical figure, learned to utilize both kinds of form, making them supplement and reinforce each other in all sorts of interesting and unexpected ways. With Corelli, pure music emerges as an independent art, beautiful as sculpture and promising new powers of expression. By his successors this new promise was realized with surprising rapidity. Constantly growing more independent of extraneous aids, developing, thanks to the fruitful interaction of metrical and harmonic grouping, an unprecedented richness and variety, music became in the hands of Bach and Beethoven a strong, flexible and efficient fabric, adapted to all phases of expression and capable of forming the most complex and self-sufficient structures. Evolved from the crude gestures and cries of naïve feeling by a never-ceasing, ever-widening exertion of man's intelligence, absolute music has become in some respects the most eloquent and penetrative of the arts. III