Roman numerals

Each numeral is a chord built on that scale degree of the key.

• I  IV  V — uppercase = major
• ii  iii  vi — lowercase = minor
• vii° — the ° symbol = diminished
• ♭VII — a flat lowers the root one step (borrowed)

Sevenths (jazz)

• maj7 — major 7th, lush and resolved
• m7 — minor 7th, mellow
• 7 — dominant 7th, tense, wants to resolve
• m7♭5 — half-diminished, the minor-key ii

Try it

Open any progression, then use ◀ ▶ to transpose into any key, or press ▶ Play to hear the chords.