Roman numeral analysis is a type of musical analysis in which chords are represented by Roman numerals (I, II, III, IV, …). In some cases, Roman numerals denote scale degrees themselves. More commonly, however, they represent the chord whose root note is that scale degree. For instance, III denotes either the third scale degree or, more commonly, the chord built on it. Typically, uppercase Roman numerals (such as I, IV, V) are used to represent major chords, while lowercase Roman numerals (such as i, iv, v) are used to represent minor chords (see Major and Minor below for alternative notations). However, some music theorists use upper-case Roman numerals for all chords, regardless of chord quality.
In Western classical music in the 2000s, music students and theorists use Roman numeral analysis to analyze the harmony of a composition. In pop, rock, traditional music, and jazz and blues, Roman numerals can be used to notate the chord progression of a song independent of key. For instance, the standard twelve-bar blues progression uses the chords I (first), IV (fourth), V (fifth), sometimes written I7, IV7, V7, since they are often dominant seventh chords. In the key of C major, the first scale degree (tonic) is C, the fourth (subdominant) is F, and the fifth (dominant) is a G. So the I7, IV7, and V7 chords are C7, F7, and G7. On the other hand, in the key of A major, the I7, IV7, and V7 chords would be A7, D7, and E7. Roman numerals thus abstract chord progressions, making them independent of key, so they can easily be transposed.
Roman numeral analysis is based on the idea that chords can be represented and named by one of their notes, their root – for more details, see there the section History of that article. The system came about initially from the work and writings of Rameau’s fundamental bass.
Arabic numerals have been used in the 18th century for the purpose of denoting the fundamental bass, but that aspect will not be considered here. The earliest usage of Roman numerals may be found in the first volume of Johann Kirnberger's Die Kunst des reinen Satzes in 1774. Soon after, Abbé Georg Joseph Vogler occasionally employed Roman numerals in his Grunde der Kuhrpfälzischen Tonschule in 1778. He mentioned them also in his Handbuch zur Harmonielehre of 1802 and employed Roman numeral analysis in several publications from 1806 onwards.
Gottfried Weber's Versuch einer geordneten Theorie der Tonsetzkunst (Theory of Musical Composition) (1817–21) is often credited with popularizing the method. More precisely, he introduced the usage of large capital numerals for major chords, small capitals for minor, superscript o for diminished 5ths and dashed 7 for major sevenths – see hereby. Simon Sechter, considered the founder of the Viennese "Theory of the degrees" (Stufentheorie), made only a limited use of Roman numerals, always as capital letters, and often marked the fundamentals with letter notation or with Arabic numbers. Anton Bruckner, who transmitted the theory to Schœnberg and Schenker, apparently did not use Roman numerals in his classes in Vienna.
Common practice numerals
In music theory related to or derived from the common practice period, Roman numerals are frequently used to designate scale degrees as well as the chords built on them. In some contexts, however, arabic numerals with carets are used to designate the scale degrees themselves (e.g. , , , …).
Symbol Meaning Examples Uppercase Roman numeral Major triad I Lowercase Roman numeral Minor triad i Superscript + Augmented triad I+ Superscript o Diminished triad io Superscript number Added note V7 Two or more numbers(#-#) Figured bass notation V4-3 Superscript # and #
First inversion I6 Second inversion I6
The Roman numerals for the seven root-position diatonic triads built on the notes of the C major scale are shown below.
In addition, according to Music: In Theory and Practice, "[s]ometimes it is necessary to indicate sharps, flats, or naturals above the bass note." The accidentals may be below the superscript and subscript number(s), before the superscript and subscript number(s), or using a slash (/) or plus sign (+) to indicate that the interval is raised (either ♮ in a flat key signature or a ♯ or in a sharp key signature.
Secondary chords are indicated with a slash e.g. V/V.
Modern Schenkerians often prefer the usage of large capital numbers for all degrees in all modes, in conformity with Schenker's own usage.
Jazz and pop numerals
In music theory, fake books and lead sheets aimed towards jazz and popular music, many tunes and songs are written in a key, and as such for all chords, a letter name and symbols are given for all triads (e.g., C, G7, Dm, etc.). In some fake books and lead sheets, all triads may be represented by upper case numerals, followed by a symbol to indicate if it is not a major chord (e.g. "m" for minor or "ø" for half-diminished or "7" for a seventh chord). An upper case numeral that is not followed by a symbol is understood as a major chord. The use of Roman numerals enables the rhythm section performers to play the song in any key requested by the bandleader or lead singer. The accompaniment performers translate the Roman numerals to the specific chords that would be used in a given key.
In the key of E major, the diatonic chords are:
- Emaj7 becomes Imaj7 (or simply I)
- F♯m7 becomes ii7 (or simply ii)
- G♯m7 becomes iii7 (or simply iii)
- Amaj7 becomes IVmaj7 (or simply IV)
- B7 becomes V7 (or simply V)
- C♯m7 becomes vi7 (or simply vi)
- D♯ø7 becomes viiø7 (or simply vii°)
In popular music and rock music, "borrowing" of chords from the tonic minor of a key into the tonic major and vice versa is commonly done. As such, in these genres, in the key of E major, chords such as D major (or ♭VII), G major (♭III) and C major (♭VI) are commonly used. These chords are all borrowed from the key of E minor. As well, in minor keys, chords from the tonic major may also be "borrowed". For example, in E minor, the diatonic chords for the iv and v chord would be A minor and B minor; in practice, many songs in E minor will use IV and V chords (A major and B major), which are "borrowed" from the key of E major.
The table below shows the Roman numerals for chords built on the major scale.
Scale degree Tonic Supertonic Mediant Subdominant Dominant Submediant Leading tone Traditional notation I ii iii IV V vi viio Alternative notation I II III IV V VI VII Chord symbol I Maj II min III min IV Maj V Maj (or V7) VI min VII dim (or VIIo)
In the key of C major, these chords are
The table below shows the Roman numerals for the chords built on the natural minor scale.
Scale degree Tonic Supertonic Mediant Subdominant Dominant Submediant Subtonic Leading tone Traditional notation i iio ♭III iv v ♭VI ♭VII viio Alternative notation I ii iii iv v vi vii Chord symbol I min II dim ♭III Aug
(or III Maj)
(or IV Maj)
♭VI Maj ♭VII Maj VII dim
In the key of C minor (natural minor), these chords are
The seventh scale degree is often raised to a leading tone making the dominant chord a major chord (i.e. V instead of v) and the subtonic chord a diminished chord (viio instead of ♭VII).
In traditional notation, the triads of the seven modern modes are the following:
No. Mode Tonic Supertonic Mediant Subdominant Dominant Submediant Subtonic /
1 Ionian (major) I ii iii IV V vi viio 2 Dorian i ii ♭III IV v vio ♭VII 3 Phrygian i ♭II ♭III iv vo ♭VI ♭vii 4 Lydian I II iii ♯ivo V vi vii 5 Mixolydian I ii iiio IV v vi ♭VII 6 Aeolian (natural minor) i iio ♭III iv v ♭VI ♭VII 7 Locrian io ♭II ♭iii iv ♭V ♭VI ♭vii
- William G Andrews and Molly Sclater (2000). Materials of Western Music Part 1, p. 227. ISBN 1-55122-034-2.
- Sessions, Roger (1951). Harmonic Practice. New York: Harcourt, Brace. LCCN 51-8476. p. 7.
- Johann Philipp Kirnberger, Die Kunst des reinen Satzes, vol. I. Berlin und Königsberg, Decker & Hartung, 1774, p. 15 and plates to p. 19. It is not entirely clear, however, whether Roman numerals in Kirnberger denote scale degrees or intervals (or both).
- David Damschroder, Thinking about Harmony: Historical Perspectives on Analysis. ISBN 978-0-521-88814-1. Cambridge University Press, 2008, p. 6
- Floyd K. Grave and Margaret G. Grave, In Praise of Harmony: The Teachings of Abbé Georg Joseph Vogler.
- Gottfried Weber, Versuch einer geordneten Theorie der Tonsetzkunst, 3d Edition, Mainz, Schott, 1830-1832, vol. 2, pp. 44-63, §§ 151-158.
- Simon Sechter, Die Richtige Folge der Grundharmonien, Leipzig, Breitkopf und Härtel, 3 vols., 1853-1854. Roman numerals are found in all three volumes.
- Anton Bruckner, Vorlesungen über Harmonielehre und Kontrapunkt an der Universität Wien, E. Schwanzara ed., Wien, Östrereichischer Bundesverlag, 1950. See also Robert E. Wason, Viennese Harmonic Theory from Albrechtsberger to Schenker and Schoenberg, Ann Arbor, UMI Research Press, 1982. ISBN 0-8357-1586-8. pp. 67-84.
- Bruce Benward & Marilyn Nadine Saker (2003), Music: In Theory and Practice, seventh edition, 2 vols. (Boston: McGraw-Hill) Vol. I, p. 71. ISBN 978-0-07-294262-0.
- Taylor, Eric (1989). The AB Guide to Music Theory, Part 1. London: Associated Board of the Royal Schools of Music. ISBN 1-85472-446-0. pp. 60–61.
- Benward & Saker (2003), p.74.
- Edward Aldwell and Carl Schachter, with Allen Cadwallader, Harmony and Voice Leading, 4th edition. Schirmer, Cengage Learning, 2011 (ISBN-10: 0-495-18975-8), pp. 696-697: "As the symbol for a Stufe, the Roman numeral "I" in C major can signify a major chord, a minor chord, a seventh chord, or indeed many combinations of notes controlled by the root C. The same Roman numeral can also represent the governing harmonic function of an extended passage embracing several or many chords. In this system, therefore, one basic sign applies to all manifestations of a structural harmony, with figured-bass numerals and other symbols indicating inversions and deviations from the basic type. [...] Roman numerals can be used less to indicate local detail and more broadly, and analytically, to denote harmonic function in either the major or the minor mode. This method assumes fluent knowledge of chord quality in both modes, a skill we consider as fundamental as the recognition of key signatures."
- Heinrich Schenker, Harmonielehre, Stuttgart, Berlin, Cotta, 1906, p. 186, Example 151.
- Mehegan, John (1989). Jazz Improvisation 1: Tonal and Rhythmic Principles (Revised and Enlarged Edition) (New York: Watson-Guptill Publications, 1989), pp. 9–16. ISBN 0-8230-2559-4.