A sequence of chords consisting of intervals that do not change as the chord moves. Example below shows a major chord of C, E, and G (with the intervals of a major third between the C and E and a minor third between the E and G). This chord would be parallel to the following chord of F, A, and C (again a major chord with the intervals of a major third between the F and A and a minor third between the A and C), which, in turn, would be parallel to the next major chord consisting of G, B, D, etc. This is also referred to as parallel motion.
Play example of parallel chords