Type a chord progression — the analyzer detects the key, Roman numerals, compatible scales and mood. Works with Am, Cmaj7, F#m, Bb, G7, Dm7 and more.
Enter your chords separated by spaces. The analyzer maps each chord to its constituent notes, then scores all 12 major and 12 minor keys by how many chord tones they contain. The key with the highest score wins — with a secondary candidate shown when the result is ambiguous.
Roman numeral notation (I, ii, iii, IV, V, vi, vii°) shows each chord's function within the detected key. This helps you understand why progressions create certain emotional feelings — the V→I resolution, the bittersweet vi chord, or the tension of a diminished vii°.
Want to learn more about how harmony and chord progressions work in practice? Visit Cloud Atelier Studio for lessons on music theory, composition, and ear training — or use the Scale & Chord Finder to hear how each chord in a key sounds.