In music, a contrast chord is an auxiliary chord formed from one of the three primary triads and sharing its diatonic function. Leittonwechselklänge (German: "leading-tone contrast chords"), abbreviated Tl in major and tL in minor.
If chords may be formed by raising (major) or lowering (minor) the fifth a whole step [ parallel or relative chords], they may also be formed by lowering (major) or raising (minor) the root a half-step to wechsel, the leading tone or leitton. These chords are Leittonwechselklänge (literally: "leading-tone changing sounds"), sometimes called gegenklang or "contrast chord".
- Major Leittonwechselklänge, formed by lowering the root a half step.
- Minor Leittonwechselklänge, formed by raising the root (US)/fifth (German) a half step.
- “A Guide to the Terminology of German Harmony”, in Studies on the Origin of Harmonic Tonality, pp. xi–xv (Princeton: Princeton Univ. Press, 1990). "Published Papers", Robert Gjerdingen.