Preliminaries

Chordal Analysis

triads in C major with Roman Numeral Analysis

As shown above, triads can be built on any scale degree. In tonal harmony, chord's basic triads are identified by their relationship to the principle key of the music using roman numerals. Roman numerals are also often thought of as describing the chord's function.

There are two systems in use:

  • All upper case roman numerals. Only the chord function is identified.
  • Mixed case roman numerals, where: upper case identifies major triads, and lower case, minor ones. Here, augmented and diminished triads have an accompanying o or x. This is the version shown above.

"I" will always refer to the tonic triad of the music's key. "V" will always refer to the dominant triad of the music's key.

For example, in G major:

  • I refers to the pitches GBD
  • IV refers to CEG
  • and ii means ACE