Music theory

Music theory is the subject of composition, scales, intervals and chords.

Primary Chords

The primary chords of a scale are triads built upon the 1st, 4th and 5th scale degree. For example, if we were in C major, the primary chords are: C major , F major and G major. The tonality of the primary chords relies on the piece's key signature (being major or minor). These chords are widely used throughout contemporary and country music. They are called primary chords as the notes in each chord can be unjumbled to create the major scale they represent.

Secondary Chords

Secondary chords represent the rest of the scale degrees, being: 2nd, 3rd, 6th and 7th. Secondary chords carry the opposite tonality of the piece's key signature. For example, C major's secondary chords are: D minor, E minor and A minor. The only exception to this rule is that the 7th scale degree (B) is a diminished triad.

Relative keys

In music, certain keys can be related to each other since they have identical key signatures (equal number of sharps or flats). For example, D major and B minor are relative major/minor keys since they both have two sharps in their key signature.