What is a Modal Interchange?

Modal interchange is a harmonic technique where chords are borrowed from a parallel scale or mode that has the same root note but a different pattern of intervals. This allows composers to introduce new chord colors and emotional contrasts while still staying centered around the same tonal key.

For example, if a song is in C major, most of its chords come from the C major scale. With modal interchange, a composer might borrow a chord from C minor, such as A♭ major or F minor. These chords are not normally found in the C major scale, but when borrowed from the parallel minor scale they add darker or more dramatic harmonic color.

Modal interchange is widely used in many styles of music, including classical, jazz, rock, and film scoring. By borrowing chords from related modes, composers can create richer harmonic progressions, unexpected emotional shifts, and more expressive musical textures while still maintaining the same tonal center.