||It has been suggested that this article be merged into Diminished triad. (Discuss) Proposed since March 2012.|
In music theory, a leading-tone chord is a triad built on the seventh scale-degree in major and the raised seventh-scale-degree in minor (the leading-tone). The quality of the leading-tone triad is diminished in both major and minor keys.
Since the leading-tone triad is diminished, it is rarely found in root position. Instead, it is commonly found in first inversion. In a four-part chorale texture, the third of the leading-tone triad is doubled in order to avoid adding emphasis to the tritone created by the root and the fifth. Unlike a dominant where the leading-tone can be frustrated and not resolve to the tonic if it is in an inner voice, the leading-tone in a leading-tone triad must resolve to the tonic. Commonly the fifth of the triad resolves down since it is phenomenologically similar to the seventh in a dominant seventh chord.
On the other hand, the leading-tone seventh chord does appear in root position. For this reason, outside of the two uses listed below, a leading-tone triad is less common than a leading-tone seventh chord.
The leading-tone triad is used in several functions. Commonly, it is used as a passing chord between a root position tonic triad and a first inversion tonic triad.[need quotation to verify] The leading-tone triad prolongs tonic through neighbor and passing motion in this instance.
The leading-tone triad is also used as a dominant substitute.[need quotation to verify] Since it contains three common tones with a dominant seventh chord, it easily can replace and function as a dominant. When used at a cadence point, it creates an imperfect authentic cadence since there is no root motion from scale-degree 5 to scale-degree 1 in the bass. This type of cadence was used commonly in the Renaissance era but increasingly grew out of fashion as the common practice period progressed.
- Edward Aldwell, Carl Schachter, Allen Cadwallader, Harmony and Voice-Leading, 4th ed. (New York: Schirmer/Cengage Learning, 2010), p. 138.
- Percy Goetschius, The Theory and Practice of Tone-Relations: An Elementary Course of Harmony (New York: G. Schirmer, 1917), p. 62. Goetschius states that the chord is just another form of the V7 chord.