Guide tones
The third and seventh of a chord, the notes that define its quality and move most smoothly from one chord to the next.
Also called: guide tone, guide-tone lines, thirds and sevenths
Guide tones are the third and seventh of a chord, the two notes that determine whether it is major, minor or dominant. In common progressions they usually sit a half step or whole step from their counterparts in the next chord, so they move smoothly and carry the harmony through a passage. In a ii V I in C, Dm7 has F and C, G7 has B and F, and Cmaj7 has E and B. The seventh of Dm7, C, rises to the third of G7, which is B. The third of Dm7, F, stays as the seventh of G7. The seventh of G7, F, falls to E, the third of Cmaj7, while B holds as its seventh. Playing only these two notes gives a clear line through the changes.
Related terms
- Rootless voicingA chord voicing that omits the root, usually because a bass player supplies it, and keeps the third, seventh and an upper extension.
- Tritone substitutionReplacing a dominant chord with the dominant a tritone away, whose notes share the same tritone and resolve the same way.
- Chord-scale theoryA method that pairs each chord symbol with a scale whose notes fit that chord, for improvising over a set of changes.