Understanding Musical Keys

Early on in your musical practice, you will be introduced to the concept of musical keys.

Keys are important to understand because every key has a distinct sound created by a hallmark set of notes. Every key is based on a scale. If you play a C major scale on any instrument, you have just played the seven notes that define the key of C. The root note of the scale gives the key its name.

Characteristics of Keys

Keys come in two flavors:

  • Major.
  • Minor.

A major key has the happy sound that we associate with a major chord, while a minor key has the dark sound that we associate with a minor chord.

A song in any given key will mostly consist of notes taken from that key’s scale. Thus, a song in the key of G will primarily rely on notes in the G major scale. (Of course, this is a generalization; progressive musicians love to bend this rule.)

Understanding Musical Keys
C major scale

Every key has three major chords, three minor chords, and one diminished chord, each chord based on a note of the scale. The first, fourth, and fifth chords in a major key are major; the second, third, and sixth are minor; and the seventh is diminished. For example, the chords in the key of C are:

  1. C major.
  2. D minor.
  3. E minor.
  4. F major.
  5. G major.
  6. A minor.
  7. B diminished.

Every major key has a relative minor key that relies on the same notes and chords, but in a different order. Thus in the key of A minor, the relative minor of C, the chords are:

  1. A minor.
  2. B diminished.
  3. C major.
  4. D minor.
  5. E minor.
  6. F major.
  7. G major.

Next Week: Using and identifying musical keys