Major seventh chords aren’t used half as much as they used to be by songwriters. Back in the middle years of the twentieth century they were an essential part of hit songs like Misty.
Back then, even if a songwriter or composer didn’t include major sevenths in his song’s score, chances are improvising musicians would drop them in to add a bit of extra character. The major seventh was the defining chord of cool jazz.
Before we go any further, let’s sort out what major seventh chords actually are, and how they sound. Check out the Piano World chord tool or All Guitar Chords. Use them to work out the fingerings for a few major seventh chords, and get a feel for how they sound. Maybe improvise some chord progressions in particular keys, adding major sevenths to get a sense of how they work. They should sound quite familiar and natural.
(Remember that the Piano World tool only gives the chords in their root position - you may want to play about and listen to how they sound in their different inversions. A major seventh chord has a root position and three inversions, starting on the third, fifth and seventh notes respectively. All Guitar Chords also only gives one inversion, though it isn’t always the first one - it’s usually the one that’s easiest to play, favouring open positions rather than barre chords).
For music readers among you, this is C major seventh (Cmaj7) in its root, first, second and third inversions:
Anyway, major sevenths are still pretty popular as passing chords these days, but few songs are really built around them. After their heyday in the forties and fifties, major sevenths took a hit in the late fifties and sixties as rock’n'roll and R’n'B grew in mainstream popularity - both are styles that favour a bluesy sound and/or simple chords. They took another beating with the advent of punk in the seventies.
Why? Because major sevenths have often been associated with sloppy, mulchy sounds: easy listening and mood music are full of them. Yet quite a few really great modern pop songs have made heavy use of major sevenths - think of The Carpenters’ Rainy Days and Mondays for an example.
But they’ve never really gone away, and have crept back into the mainstream via genres like funk and acid jazz - you can hear a lot of them in the songwriting of acid jazz bands like Jamiroquai. (Lots of minor sevenths in Jamiroquai’s stuff, too - but we’ll deal with them another day).
Play about with major sevenths in your own songwriting. If you’re writing in a major key, you’ll mainly use them on the tonic and fourth (subdominant) chords - that’s C and F in C major, E and A in E major, and F and Bb in F major. They don’t work on the dominant (G in C major, B in E major, C in F major, and so on) because those chords naturally take dominant sevenths (i.e., they become G7, B7 and C7), and their seventh notes are minors - that is, a tone flatter than a major seventh chord. Use one of the chord tools to check out the differences between C major seventh (Cmaj7) and C dominant seventh (C7) to see what I mean here.
As a final example, listen to these two chord progressions: they are essentially identical in terms of their basic harmony, but the first is built on basic chords (triads and dominant sevenths) whereas the second has had major seventh chords added. The key is Eb major. I’ve included the score for each progression, plus a sound file in which both are played, in order:
Progression 1 - without major sevenths
Progression 2 - with major sevenths
And here’s the mp3 - progression 1 first, followed by progression 2 with a couple of seconds’ break in the middle:
Like I said, with major sevenths added to the tonic (Eb) and fourth/subdominant (Ab) chords the progression is harmonically the same - an identical tune would fit over the top of both. But the added major sevenths change the chords’ character quite dramatically.
