G7 and D♭7 leading to C
G7 contains G–B–D–F. D♭7 contains D♭–F–A♭–C♭, where C♭ sounds like B. The third and seventh trade roles while retaining the same two pitches. D♭7 can replace G7 before C, with the substitute’s bass moving down a semitone. This tool may display B instead of C♭ because its note labels use a fixed pitch-class spelling.
Compare the resolution
Listen to the dominant, then the destination major or minor chord. Repeat with the substitute. The change in bass motion is part of the effect, so compare in the context of a phrase. Extended dominants may also provide the required guide tones, but their tensions need separate consideration; the suggested substitute here is a plain dominant seventh.
Explore secondary dominants
Use the destination buttons to load a dominant leading to another major or minor chord in your reference key. In C major, A7 leads to Dm; its tritone substitute is E♭7. The tool shows the selected dominant’s core, the shared tones and possible destination chords. A diminished destination is omitted from this set of examples.