Closely connected with the dance is _music_, the preparatory stage of which is constituted by the participation of the voice in the rhythm of the external movements of the body. These articulatory movements, which form a part of the mimicking activity of the face, supplement the dynamic rhythm of the dance with the melodic rise and fall of tones. The emotion which finds its outlet in the dance itself, then seeks a further enhancement through objective means. These means also involve the activity of the bodily organs; noises are produced by clapping the hands, by stamping on the ground, or by the rhythmic clash of sticks. In the latter case, the transition from instruments of noise to those of tone is easily made. The earliest forms of tone instruments are of two sorts, according as they copy the production of sound by external means, on the one hand, or by the vocal organs, in the accompanying tones, on the other. Thus, the two original forms of musical instruments are _instruments of concussion_ and _wind instruments_. In origin, these are directly connected with the dance. They are natural means of intensification created directly by the emotion, though later modified by systematic invention. The later development of musical art continues to remain in close relation to the two main forms of the dance, the solemn ceremonial and the ecstatic dance, between which there come to be numerous transitions. From the most primitive to the highest stages of music, we continually find two sorts of musical expression, the _sustained_ and the _animated_. These correspond to the contrasting feelings of rest and excitement, which are experienced even by animals, and which man therefore doubtless carried with him from his natural state into his cultural life. With the progress of culture, these feelings constantly become more richly differentiated.