What does "atonality" refer to in music?

Atonality refers to a musical approach that intentionally avoids establishing a key or tonal center, which is a significant aspect of many traditional music forms. In tonal music, melodies and harmonies are constructed around a central note (the tonic), creating a sense of resolution and coherence. However, in atonal music, composers create works that do not adhere to these conventional tonal frameworks, treating all pitches as equal without hierarchy.

By rejecting established tonalities, atonality allows composers to explore a wider range of sonic possibilities and textures, leading to innovative forms of expression. This approach is most commonly associated with 20th-century music, particularly with composers such as Arnold Schoenberg and Anton Webern, who sought to break free from traditional harmonic constraints.

The other options place emphasis on defined structures often found in tonal music, where traditional harmonies, rhythmic complexity, or major and minor scales play central roles, which are not applicable in atonal music's framework.