What term describes the absence of a specific key, tonality, or mode in a musical composition?

Atonality refers to the absence of a specific key, tonality, or mode within a musical composition. It signifies a break from traditional tonal structures, where music is typically organized around a central pitch or key. Atonality emerged prominently in the early 20th century, with composers such as Arnold Schoenberg leading the way in exploring this method of composition. In atonal music, there is no single home note or chord that serves as a point of resolution, allowing for a wide range of emotional expression and complexity.

Polytonality, bitonality, and quartal harmony refer to different concepts. Polytonality involves the simultaneous use of two or more different keys or tonal centers, whereas bitonality specifically employs two distinct tonalities at once. Quartal harmony, on the other hand, is a harmonic structure based on intervals of fourths rather than the traditional thirds, and does not inherently indicate the absence of tonality. Thus, the most accurate term for describing a composition that lacks a specific key or tonality is atonality.