Roman Numeral Analysis

Building triads on top of each note of a scale will produce chords of different qualities. These chords are identified using Roman numerals.

The number used is determined by the root. If the root is scale degree 1 (the tonic), a Roman numeral I/i is used. A Roman numeral II/ii is used if the root is scale degree 2 (the supertonic), and so on. Capital letters are used for major or augmented chords, and lower-case letters are used for minor or diminished chords.

Since the intervals within a major scale are the same in every key, the chord qualities are the same in any major key.

The chord qualities are different in a minor key. Note that the harmonic minor is generally used.

The harmonic structure of a piece can be broken down using a Roman Numeral Analysis by following these steps:

1. Determine the key of the piece.
2. Write out the scale for that key.
3. Create triads on each scale degree to determine the available primary chords.
4. Examine each chord in the piece and match it to the primary chord.

Practice Exercises