Previously we talked about dominant seventh chords, which are constructed by adding a minor seventh to a chord. Adding a major seventh instead is a very “jazzy” thing. With it, you can jazz up any chord, not just the dominant.

A major seventh is one semitone below the octave, so it forms a highly dissonant minor second (a single semitone) against it. This adds a lot of tension but, unlike the dominant seven, major dominant seventh doesn’t have an obvious resolution, so it provides an element of excitement and unpredictability.

Major-seventh chords are usually voiced in such a way as to put distance between the seventh and the root. But you can try this slightly unusual grip, in which there is a semitone interval between the two highest strings (although the third of the triad is missing, so it’s a variation of a power chord).

The notation for major-seventh chords varies–in jazz, the major seventh is often marked with a triangle, as in $\Delta 7$. It’s also common to see Maj in front of 7.

You may think of major-seventh chords as constructed either by lowering the root by a semitone, or raising the seventh of the corresponding dominant seventh chord.

Here’s the E major-seventh grip, together with its less common minor version:

When transposing these chords down the fretboard, we often skip the fifth in the bass as well as the root on the highest string. We either mute these strings or finger-pick the remaining four strings. Here’s the G major-seventh chord constructed this way:

You might be wondering at the resemblance of this grip to A minor. This is no coincidence–the major-seventh chord contains a minor triad. Check this out: there is a minor third between 3 and 5, and a major third between 5 and $\Delta 7$. In fact, every four-note chord contains two triads (the dominant seventh chord contained a diminished triad built inside a tritone, and the minor major-seventh chord contains an augmented triad).

Here are, similarly constructed, major-seventh versions of A chords. They are also easy to transpose down the fretboard. (Can you spot a flatted Dm shape in the first one?)

And these are the D chords:

C major-seventh is an odd one (that’s because there is an open string between the minor seventh and the root), but it’s very easy to grip:

If you squint hard enough, you can see the elements of E minor in it.

Here’s the open-string version of G major-seventh:

Squint again, and you can see the elements of B minor.