ABSTRACT
The late nineteenth and early twentieth centuries saw the decline of the tonal system, which had been an important organizing factor in music since the early Baroque period. Conventional harmonic progressions still occur with some frequency, especially at cadences, in works from the early part of the twentieth century. Before examining how tonality is established in pitch-centric works, let us review how this was accomplished in traditional tonal harmony. One important element was a descending perfect-5th root movement to tonic combined with a half-step leading-tone motion, also to tonic. Atonality was a development even more radical than that of the various sorts of pitch-centricity used in post-tonal music. Melodies play a larger role in determining the pitch center than was the case in tonal music. The declining interest in the vertical dimension is exemplified by linear counterpoint, in which the "chords" seem truly to be mere simultaneities created by the relatively uncontrolled relationships between independent lines.
