Celine Dion: The Beauty of Common-tone Modulation
Artists featured: Celine Dion, Engelbert Humperdinck, G. Bizet
This post discusses the usage and pleasant effect of common-tone modulation — a harmonic technique where a piece of music changes keys (i.e., modulates) via a sustained note belonging to both the old and new key (i.e., a common tone).
Common-tone modulation is effective in adding harmonic momentum to a tune, and/or transporting the listener to a distant yet intelligible key — the unexpectedness being the center of the satisfaction.
My favorite example of this technique from pop music, and arguably the second-most iconic key change of the genre, is the climax of Celine Dion’s (or, more accurately but less notably, Eric Carmen’s) timeless lamentation, “All By Myself.”
After a charming yet somewhat restrained two and a half minutes in A major, the song approaches its epic turning point. At 2:44, Dion sustains a powerful F5, which is the third of the key’s minor iv chord, D minor. (Here I must acknowledge that the D minor chord (along with the note F) does not belong to the key of A major; however, the minor iv chord is a very popular borrowed chord in major keys, and thus I consider this excerpt an apt example of the technique in question.)
(At 2:29, with common tone at 2:44 and key change at 2:48)
Dion uses this note as a bridge between A major and the faraway Db major, within which the note F represents the third scale degree. Theory fans and casual listeners alike cannot help but sense the passion and color sparked by this clever harmonic pivot.
Another 20th-century power ballad to make use of this device is Engelbert Humperdinck’s “A Man Without Love,” a 1968 hit single and English adaptation of the Italian “Quando M’innamoro” from the same year.
In the middle of the second chorus, Humperdinck et al. bring us up a semitone from the key of D major to Eb major via common-tone modulation. While trivial at face value, as this represents the shortest “distance” of modulation possible within the Western 12-note system, the harmonic underpinnings at play are quite artful.
As the second phrase of the chorus comes to an end over a V-I cadence, the melody and harmony respectively land on the tonic pitch and chord. Then, right before entering the third phrase, the melody preserves the tonic D4 pitch while the harmony shifts from a D major chord to a Bb dominant 7th chord, tonicizing the new key of Eb major. We can observe that the note D is present in both a D major chord ([D F# A]) and a Bb7 chord ([Bb D F Ab]).
(At 2:21, with common tone at 2:29 and key change at 2:31)
Desperate enough lyrically, the refrain is given extra energy and emotion by this harmonic ascension.
It is worth noting that the first verse of the song also changes keys from D major to Eb major. However, it does not rely on a common tone to pivot between the two keys, here simply opting to jump directly to Eb major without any kind of “set-up.” We can hear the same harmonic spontaneity, though the instance in the second chorus is delivered a bit more coherently, thanks to the common pitch.
This harmonic phenomenon is also present at the end of an exceptional aria belonging to an exceptional opera, Georges Bizet’s Carmen. Set in Db major, “La fleur que tu m’avais jetée” from Act II allows Don José to reveal the hopeless romantic residing underneath his proud military attire.
In a vulnerable and quite literal confession of his love for Carmen, tenor José sings the words “je t’aime” on Bb3 and C4, sustaining the latter and hinting at a potential V-I cadence to put the piece to rest (C is the leading-tone of the key of Db, and relatedly is the third of the key’s V chord, Ab major). The harmony then repurposes this C pitch to momentarily bring us to the unrelated key of F major, C serving as the 5th scale degree of the new key. With José still pleading on the same note, the harmony performs a V-I cadence in F (with C as the root of the V chord and the fifth of the I chord).
(At 3:33, with common tone at 3:45 and key change at 3:47)
We then hear an equally unexpected yet more cathartic shift back to the original key of the tune. Bizet, in his harmonic wizardry, commands José to dramatically pull his C up to a C# (enharmonically equivalent to a Db), yielding a mysteriously tense F augmented chord before using the new note to pivot back to the home key and tonic chord of Db major.
(At 3:43, with 2nd common tone at 3:52 and key change at 3:54)
In a mere ten seconds, Bizet sends us on a harmonic journey of incredible substance, gracefully punctuating Don José’s serenade with some of the most delightful bars of music the opera has to offer.
Key music theory idea: shifting key centers via a sustained melodic pitch
