Music theory can be a little overwhelming for someone new to the subject. With all the different terms, concepts, and symbols, it’s easy to get lost in the jargon.

One of those terms that you may have come across is “7” or “seventh.” In this article, we will uncover what 7 means in music theory.

What is a seventh?

In music theory, a seventh refers to the interval between two notes that are seven letter names apart. For example, the interval between C and B is a seventh. The distance between these two notes is seven steps or half-steps.

Types of Sevenths

There are three types of sevenths: major seventh (M7), minor seventh (m7), and diminished seventh (dim7). Let’s take a closer look at each type.

Major Seventh (M7)

A major seventh is an interval consisting of seven letter names and eleven half-steps. For example, the interval between C and B is a major seventh. The symbol for a major seventh is “M7.”

Minor Seventh (m7)

A minor seventh is an interval consisting of seven letter names and ten half-steps. For example, the interval between C and B flat (Bb) is a minor seventh. The symbol for a minor seventh is “m7.”

Diminished Seventh (dim7)

A diminished seventh is an interval consisting of seven letter names and nine half-steps. For example, the interval between C and B double flat (Bbb) is a diminished seventh. The symbol for a diminished seventh is “dim7.”

The Dominant Seventh Chord

The most common use of 7 in music theory is as part of the dominant seventh chord. A dominant seventh chord is a four-note chord consisting of a major triad (root, third, and fifth) and a minor seventh interval. For example, the dominant seventh chord in C major would be C7 (C, E, G, Bb).

The dominant seventh chord is used extensively in various genres of music and often functions as a tension chord that resolves to the tonic (the first note of the scale) or another chord in the key.

Conclusion

In summary, 7 in music theory refers to the interval between two notes that are seven letter names apart. There are three types of sevenths: major seventh (M7), minor seventh (m7), and diminished seventh (dim7).

The most common use of 7 is as part of the dominant seventh chord, which consists of a major triad and a minor seventh interval. Understanding these concepts will help you navigate music theory with ease.