What is the meaning of atonal music?

Atonal music is defined as music that lacks a tonal center or key. This means that atonal compositions do not adhere to traditional harmonic conventions, which often revolve around a specific tonality that provides a sense of home or resolution. Instead, atonal music embraces dissonance and the use of all twelve pitches in the chromatic scale without establishing a hierarchy of notes, allowing for a free exploration of sound and expression.

For example, in atonal pieces, you will not find a melodic line that feels centered around a particular note or chord, as you might in tonal music, where melodies typically converge towards a tonic note. This lack of a key center can create a very different listening experience, often challenging listeners' expectations of musical structure.

In contrast, the other options describe characteristics of tonal music, which relies on a clear melody, strict rhythm, or adherence to specific scales, all of which are fundamentally different from the principles that define atonal music.