Tonsystem

Tonsystem, or tonal system, is a framework in Western music theory in which pitches and chords are organized around a central pitch called the tonic. In this system, melodies and harmonies create a sense of tension and resolution by moving between pitches and keys, with the identity of a piece often tied to its key center.

The system uses diatonic scales of seven notes, standard intervals, and functional harmony. Chords and progressions are understood in terms of functions such as tonic (stability), subdominant (preparation), and dominant (tension leading back to the tonic). Modulation to related keys and cadences establish and confirm a tonal center.

Historical development: The tonal system matured in the Baroque period and became the foundation of the Classical and Romantic eras. It grew from earlier modal concepts and was reinforced by the widespread adoption of equal temperament in the 18th century, which allowed more flexible key changes. The system remains dominant in much Western art music, though later composers have explored modal, atonal, and other approaches.

Tuning and variants: Besides equal temperament, earlier tunings such as just intonation or mean-tone affected interval sizes and chord colors. While alternative tuning systems and microtonal concepts exist, the tonal system centers on relationships among scale degrees and a persistent tonic, rather than on fixed freetone pitch sets.

In broader terms, tonality contrasts with atonality, or with non-Western tuning and conceptual frameworks, which do not privilege a single tonal center. The term tonality is often used interchangeably with tonal system to describe this approach to organizing pitch in Western music.