A melody can maintain the same harmonization each time it appears, yet be varied through changes in voicing, voice-leading and instrumental texture. Yet in some cases the harmonization itself changes: Different pitches support the melody. J.S. Bach’s Chorale Harmonizations are the Common Practice “Bible” of reharmonization: Bach composed over 200 Cantatas and several large Masses, all incorporating Lutheran hymn tunes. Not only did Bach revisit the same hymn tune in different Cantatas, he typically incorporated a hymn tune into multiple movements of the same work. He did so with supreme imagination, often never repeating the same harmonization twice.
Here are the concluding phrases of two settings of the Chorale tune, “Jesu Leiden, Pein und Tod” from J.S. Bach’s St. John Passion. If you aligned the two excerpts on top of each other, only the last two chords would be the same. (American composer Donald Martino’s landmark edition of the Bach Chorales places the multiple harmonizations on top of each other and transposes them to the same key, making them easier to compare.)
Two primary means of reharmonizing a melody are to vary the amount of chromaticism and change the mode. Franz Liszt’s Totentanz provides examples of both. Totentanz is a fantasia on the Dies Irae chant introduced in the first module of “Hearing Harmony.” Liszt presents this medieval melody in many different harmonic guises.
In this example, the melody is supported by a diatonic progression in minor.
This version widens the harmonic palette with more chromaticism.
In this magical passage, Liszt recasts a fragment of the theme in Major. If you hear a dash of chromaticism at the end—you’re right!
Jazz improvisers are celebrated for their high octane, spontaneous reharmonizations. Here is the traditional harmonization of the Christmas song O Tannenbaum.
Compare that with Wynton Marsalis’ fanciful reharmonization.
Listening to reharmonization is like watching a favorite actor take on a new role: You recognize the actor’s identity but marvel at his or her fresh “persona.” Diatonic harmonizations may feel more tightly “scripted.” Added chromaticism makes it seem as if the actor is ad. libbing. When there is a change of mode, it is as if a performer better known for comedy takes on a serious role or one typically cast as the villain plays a romantic lead.
When you recognize a melody’s refrain, try to discern if it is harmonized differently. If it is, evaluate how extensive the changes are: Does the progression differ only in a few details or is it substantially new? Is the chromaticism increased? Is there a change of mode?