Measures forty-seven through forty-nine exhibit a greater sense of dissonance than Evans had experimented with since the onset of the improvisation. Some writers have suggested that he is employing bi-tonality or atonality here, however I disagree with that assessment.
Over the tonic-dominant ostinato, Evans plays a melodic line, one might even suggest it’s a “lick,” that is based on the whole-tone scale. Since the WT scale is symmetrical and lacks a leading-tone and tonic, one cannot accurately describe it as bi-tonal. Moreover, “Peace Piece” has a tonal center — the pitch of C, so the assertion of atonality does not correctly describe the phrase either. The piece is still in C major; he is merely exploring notes (and their respective timbres) that lie outside of the scale.
This Quiet Fire 