What are Guide Tones?

Guide tones are the notes in a chord that most clearly define its harmonic quality and function. In many styles of music—especially jazz—the guide tones are usually the third and seventh of the chord. These two notes determine whether a chord is major, minor, dominant, or another type.

For example, in a C7 (C dominant seventh) chord, the notes are C, E, G, and B♭. The guide tones are E (the third) and B♭ (the seventh). These two notes establish the chord’s identity and its tension, while the root and fifth are often considered less essential because they do not define the chord’s quality as strongly.

Guide tones are especially important in jazz improvisation and chord voicing. Musicians often focus on these notes when creating melodic lines or when comping with chords, because the movement of the third and seventh from one chord to the next clearly outlines the harmonic progression. This smooth movement between guide tones is known as guide tone voice leading, and it helps make chord progressions sound connected and cohesive.