Atonal music is a style of composition that avoids establishing a key or tonal center. Unlike traditional music, which often revolves around a specific note or chord, atonal music uses all twelve notes of the chromatic scale equally. This approach creates a sense of dissonance and unpredictability, challenging listeners' expectations. Developed in the early 20th century, atonal music is often associated with composers like Arnold Schoenberg and Alban Berg. These musicians sought to break free from conventional harmonic structures, leading to new forms of expression in the world of classical music. Atonality has influenced various genres, including jazz and experimental music.