Organization of music around a single pitch; more specifically, the Western system of key s that grew out of the modal music of the Renaissance in the 17th century.
The term is often used to refer to the network of relationships implicit in the seven principal tones of a given key, each of which has the potential to become the tonic temporarily by means of modulation , whereby a new network of relationships arises. Because of its capacity to extend pitch relationships to remote lengths in an audibly comprehensible way, the tonal system permits the composition of music of great complexity.