Universal Key - Triads (jazz and Popular Style)

Triads (jazz and Popular Style)

In music theory aimed towards jazz and popular music, all triads are represented by upper case numerals, followed by a symbol to indicate if it is not a major chord (e.g. "-" for minor or "ø" for half-diminished):

• E♭maj7 becomes I maj7
• F -7 becomes II -7
• G -7 becomes III -7
• A♭maj7 becomes IV maj7
• B♭7 becomes V7
• C -7 becomes VI -7
• Dø7 becomes VIIø7

When representing the triads rooted in a minor key, accidentals are used to indicate the chromatic alteration from the assumed major key roots indicated by numerals that don't have accidentals:

E♭- (minor):

• E♭ -7 becomes I -7
• Fmø7 becomes IIø7
• G♭maj7 becomes ♭IIImaj7 (the assumed pitch for the root of a III numeral in E♭ is G, and the ♭ is required to indicate that, in E♭-, this chord is rooted on G♭)
• A♭ -7 becomes IV -7
• B♭ -7 becomes V -7
• C♭maj7 becomes ♭VImaj7
• D♭7 becomes ♭VII7

This will frequently result in numerals whose accidentals are different than those of the actual root note, as they are referring to a change from the assumed pitch and not an absolute pitch:

D- (Minor):

• D -7 becomes I -7
• E -ø7 becomes IIø7
• F maj7 becomes ♭III maj7 (the assumed pitch for the root of a III numeral in D is F♯, and the ♭ is required to indicate that, in D-, this chord is rooted on F)
• G -7 becomes IV -7
• A -7 becomes V -7
• B♭maj7 becomes ♭VI maj7
• C7 becomes ♭VII7