Music theory relies almost entirely on church modes and considers the blues as an outsider. Yet almost all pop music since The Beatles (also called The British Invasion) is influenced by the distinctive mix of blues and church modes. It’s time to set the record straight.

Minor over major

The foundation of the blues is formed by pentatonic scales, 5-tone (penta) as opposed to the 7-tone church scales. Available in both minor and major versions. The striking thing about the blues is that you can use the notes of a minor pentatonic scale in a major key. So a blues in C major can approached as pentatonic in C minor. You can hear this in the blues vocals, in which the minor third (the 3rd stage) from the pentatonic minor mode over a major chord provides the characteristic “complaining, wailing” sound. It is also used in the same way in soul, funk and so on. Blues guitarists and almost all pop and rock instrumentalists use this scale. The minor pentatonic scale is without a doubt the most used scale among pop and rock guitarists.

This does not apply to church scales and classical music, playing minor over major is considered a harmonic error.

Ebony & Ivory

On the keyboard, these pentatonic scales are easy to visualize: the black keys form pentatonic scale, while the white keys comprise the church scales. Together they include the 12 tones we can choose from when making music, at least for Western music, as there are of course countries like India that use quarter notes.

In the 18th century however that color scheme was reversed.

Well it’s a one for the money

The rock ‘n’ roll leans completely melodically and harmonically on the blues. Rock ‘n’ roll = minor pentatonic over major chords. A good example is Blues Swede Shoes by Elvis Presley. The opening notes where he sings “Well it’s a one for the money, two for the show” are A and C, the tonic and the minor third. But the song is in A major, so according to classical music theory you would expect a major third, a C # instead of a C. But what Elvis is singing is the minor blue note (the C). So this work is completely at odds with the old classical approach. It sounded completely new at the time, at least to white people.

Innovation from England

The Beatles continued to elaborate on rock ‘n’ roll. Their sources of inspiration were Elvis, Buddy Holly, Chuck Berry and so on, but they mixed that music with…. drum roll: church scales!

While The Beatles have always said they weren’t too concerned with understanding music theory, they were well aware of the twist they put on rock ‘n’ roll.

In the great book The Complete Beatles Recording Sessions by Mark Lewisohn you will find a quote by Paul McCartney who discusses the third single of The Beatles From Me To You:

As far as I am concerned, the magic of that song takes place earlier in the song. From Me To You is not in the blues idiom, they stay in C major (Ionic). So there is no question of “minor third over major third chord”. Until John Lennon suddenly introduces a F7 chord and sings “Just call on me”, emphasizing the minor seventh (when he sings “call”) of the F chord. But F7 doesn’t belong in C major so what the F is going on here then? F7 would indicate Bb major or Bb minor, but certainly not C major. Well, at that specific moment John Lennon is singing the blues for a moment. For a moment that blues idiom is used.

The Beatles have beautifully interwoven the blues and classical idioms together in a song. Approaching something as if it is a blues and add western classical modes in the chorus, or vice versa. Or sometimes, as in From Me To You, for example, they just quote the blues for one measure. This is one of the aspects that makes The Beatles’ music so brilliant in my opinion. They’ve built a bridge between Berry and Bach.

Many music theorists are missing this aspect. They exclude the blues and see the note Lennon sings in “Just call on me” as a strange outside note. But it’s not, it’s just the blues, or rock ‘n’ roll (which has its foundation in the blues).

How do you recognize the blues?

As I explain in my example From Me To You, it is actually quite easy to recognise the blues. When, according to the rules of classical music theory, something is seen as a strange, or even wrong note, there can be two things: indeed a harmonic error (read: the note does not fall within a known musical idiom), or it’s a blue note.

The tonic (the 1st stage in a scale) in major according to classical music theory is always a major seventh (major seventh). In the blues, however, this is a dominant seventh chord. According to classical music theory, the dominant seventh chord always plays the role of the dominant, the chord forces (tension) to return to the tonic (relaxation, rest). So after a G7 a C follows.

This works differently in blues music. In blues a G7 might as well be the tonic, the subdominant, or the dominant. A blues only consists of chords with minor sevenths. Actually, the blues is a matter of parallel shifts of minor seventh chords or what we also call The Devil’s Interval, also known as tritone: the diminished fifth (5th stage).

For example, a blues in C exists over these 3 tritones:

• Bb E (in C7 chord)
• A Eb (in F7 chord)
• B F (in G7 akkoord)

The major third and minor seventh form a tritone. The blues thus consists of three tritone chords: the tritone of the root, the tritone that is half a note lower, and a tritone that is half a note higher than that of the root. In short: the tritonuses in a blues take place in the range of just a whole note.

You can’t play a church scale over a blues from the first step, the Ionic. That does not sound right. You have to use a pentatonic minor scale, pentatonic major or Mixolydian scale.

The interesting thing about the blues is that the minor seventh does not play the role of dominant. And the subdominant is not a major 7, but also a minor seventh. That IV (4th stage) can therefore no longer be called subdominant. As I noted above, the blues consist of parallel shifts of minor seventh chords. And those therefore do not have a dominant-tonic relationship. They are in fact just parallel shifts of the devil’s interval.

To return to the question “How do you recognize the blues”, I think this is quite easy to answer: we are in the blues idiom when a minor seventh chord does not have the function of the dominant. For example, just as Lennon applies that to the F7 chord in “From Me To You.” His F7 does not force you to go to Bb, Lennon is simply singing the blues. Therefore, consider that chord the tonic of a blues in F. You can therefore pentatonic solo over that F7 in F minor. For example, choose a lowered third in your solo. This way you are playing bluesy. According to classical music theory a mistake, but no, we are good.

We Can Work It Out

A striking title in this regard and a good example song: We Can Work It Out by The Beatles. The song is in D major. But the D chord is alternated with a C chord which does not belong to the key. Weird? No, because The Beatles apply the blues. Play a Dmaj7 instead of a D chord and try singing the verse. Indeed, that does not sound good! On the other hand, D7 does sound okay. So D7 is the tonic, which also indicates that The Beatles are playing the blues. This is also expressed when you solo pentatonic over the verse in D minor. That sounds wonderful in contrast to D Ionic which sounds wrong.

This is a fact that a few theorists take into account. Even the great analysis by Alan W. Pollack of The Beatles’ material lacks the obvious blues link here and there. For example, in his analysis of We Can Work It Out, the term blues or pentatonic is not mentioned. However, that song is his first analysis that he published online. In later analyzes of other Beatles songs, the term blues is used often.

My theory

I put it simple: in pop music there are two different idioms, each of which has its own set of rules. The above argument should therefore be seen as a clear explanation between those two idioms: Western classical music and the blues. Think of both “systems” as different algorithms, as different idioms that we can choose from.

And especially The Beatles and their followers have ensured that both idioms in a piece of music can go together well. Since The Beatles, we have found it very normal that the church modes and the pentatonic approach go well together. This has enriched the pallet of western music.

In my opinion, the essence of my essay boils down to the following: a dominant 7 chord does not always have to be dominant. Thanks to The Beatles and the blues!