Non-Chord Tones in [59] "Yesterday"

Continuing my blog from February 2, this one will look at non-chord tones used in the song "Yesterday" and why they help establish the nostalgic mood of the song.

The term "non-chord tone" is used to refer to any musical note used in a melody that is absent from the accompanying chord.  For example, the chord C major consists of the tones c, e, and g. Any melodic note heard against that C major chord other than c, e, or g is considered a non-chord tone because it is not part of the chord.

In essence, a tone that is not part of the accompanying chord is dissonant. Dissonances provide spice to music and thus can be an extremely effective way of creating particular emotional content in music. 

And in "Yesterday", non-chord tones are used extensively to help capture the emotional and nostalgic feel for which the song is so famous. The example below (click on it to enlarge) shows several non-chord tones of the verse shaded green.

Indeed, the very first sung words feature such an instance. The opening chord is an F (in this case consisting of f and c - but no a) while the opening syllable is sung on the tone g, dissonant against f. The next two syllables ("ter-day") are both f's, which resolve that dissonance. Two measures later, on the word "far", the pattern is repeated. The word is sung on the pitch e against a D minor chord (consisting of the tones d, f, and a), resolving on the following two syllables ("a-way") to d. Both of these uses of non-chord tones resolve from the second scale degree to the first. The next instance is very similar, but uses the fourth scale degree resolving to the third. The word "here" is sung on a b-flat, dissonant against the chord F (consisting of f, a, and c), resolving to a. This particular pattern of non-chord tone resolution produces a "sighing" motive that carries a certain emotional content that parallels a similar feel established by the lyrics.

But of course, Paul McCartney is hardly the only composer to use this trick. Taylor Swift's cover of "Last Christmas", which was broadcast seemingly incessantly over the radio this past holiday season, uses the exact same pattern (same starting note against the same staring chord, with a resolution descending by step, and with lyrics displaying a similar character and degree of emotional content):

Nor is Paul McCartney the inventor of this trick. Though non-chord tones have been used for many centuries, their full expressive capability was unleashed during the Romantic Era (roughly 1800-1900), in which composers consciously embraced emotional expression through their musical production. Tchaikovsky's Symphony No. 5 (1888) uses non-chord tones rather similar to those in "Yesterday", both employing highly expressive "sighing" motives in which the dissonance resolves through descending by step. In the graphic below of the famous horn solo at the start of the second movement, these dissonances are shaded green.

The first two of these three non-chord tones resolve as 2-1, with the third resolving as a 4-3 - just like those found in "Yesterday".