Select Key
C majorKey of C
View
Diatonic Chords & Inversions
Key
C majorKey of C
What chord is this?

Select the notes present in your chord (by pitch class, regardless of octave), then click Find Chord. Results show all diatonic and secondary dominant matches in the chosen key.

No notes selected
Key
C majorKey of C
Identify from Bass Note

Select a bass note to see every chord in the chosen key that could have that note in the bass, along with the Roman numeral and inversion it implies.

Root Note
CRoot note
Order
Church Modes

Harmonicon · Created by Ben Perche with Claude.ai

About Harmonicon

Reading the chord tables

Click any chord to expand its inversion table. The bass note (underlined in red) is the lowest note of the chord — it determines the Roman numeral suffix. The chord tones column lists notes in root-position order; the 7th is shown in italics and is optional (include it for a richer sound, omit it for a plain triad). In the 3rd inversion the 7th is itself in the bass and is underlined accordingly.

Figured bass suffixes

No suffix = root position · ⁶ = 1st inversion (3rd in bass) · ⁶₄ = 2nd inversion (5th in bass) · ⁷ = root-position 7th chord · ⁶₅ = 1st inv. 7th · ⁴₃ = 2nd inv. 7th · ⁴₂ = 3rd inv. 7th (7th in bass) · °⁷ °⁶₅ °⁴₃ °⁴₂ = diminished 7th and its inversions.

Chord by function view

Switch to By Function in the View panel to group chords by harmonic role rather than type. Tonic (T) chords provide stability and rest. Pre-dominant (PD) chords build tension toward the dominant, including the Neapolitan and augmented sixth chords. Dominant (D) chords create the tension that resolves back to tonic. Extended & Chromatic covers secondary dominants that tonicise other areas, borrowed chords, and common-tone chords.

Special chords

Augmented sixth chords (It⁺⁶, Fr⁴₃, Ger⁶₅) have ♭6̂ in the bass and ♯4̂ on top, creating an augmented 6th interval that expands outward to the dominant. The Neapolitan (N⁶) is a major triad on ♭2̂, almost always in 1st inversion, functioning as a pre-dominant. Borrowed chords come from the parallel minor (in a major key) or parallel major (in a minor key). Common-tone (CT) chords share one note with the chord they embellish — the sustained pitch is named in the chord description.

Note spelling

Note names follow the native spelling of the selected key (sharps for sharp keys, flats for flat keys). For keys with enharmonic equivalents (e.g. F♯ / G♭), click the outer ring of the circle of fifths to switch to the enharmonic spelling.