What term describes music characterized by the total absence of any tonal center and unresolved dissonances?

The term that describes music characterized by the total absence of any tonal center and unresolved dissonances is atonality. Atonality signifies a departure from traditional tonal music, where pieces are structured around a central pitch or key. In atonal compositions, there is no single note or chord that serves as a home base; instead, all pitches are treated equally, which leads to a sense of instability and lack of resolution in harmonies. This approach allows composers to explore more complex textures and emotional landscapes without the constraints of tonality.

In contrast, polytonality involves the simultaneous use of two or more different keys, creating a rich and complex sound but still maintaining some reliance on tonal centers. Expanded tonality refers to a situation where traditional tonal elements are expanded or altered, often incorporating unfamiliar scales or harmonies while still maintaining a sense of tonality. Functional harmony, on the other hand, is rooted deeply in tonal music, where chords and progressions serve specific roles that lead towards a resolution based on established harmonic rules. Thus, atonality stands out as the term most accurately reflecting the absence of a tonal center and the use of dissonant harmonies without resolution.