John Coltrane's album "Giant Steps," released in 1960, introduced a new kind of composition to the list of jazz standards, and thus made a mark on the history of jazz. This new kind of composition features a harmonic progression that alternates between tonic and dominant chords in three different keys and that moves by major third from key to key; this kind of progression is exemplified by three famous Coltrane compositions. What is particularly striking about this kind of progression is that it reveals a duplicity in the voice-leading pattern connecting major triads and their respective dominant seventh chords: the same voice-leading pattern that takes a major triad to its own dominant seventh chord (one voice holding a common tone, while two other voices move in contrary motion by semitone) may also take it to a dominant seventh chord whose root is a minor third above the root of that triad, and vice versa. The paper will focus on such aspects of voice leading in the progression itselfand on how they are reflected in a group of Coltrane's compositions: "Giant Steps," "Countdown," and "26-2."