Omnichord OM-108 Chord Helper

Enter a chord symbol (e.g. AbM7/F, Cm/Eb, F/C, G9, A#). The app suggests OM‑108 playable chords and similar substitutions (always ≥50% note coverage). Click a chord to visualize and hear it.

MAJ

MIN

7TH

Piano (one octave, chord tones)

Guitar

How it works:

Enharmonics normalized to OM‑108 panel (C#→Db, Gb→F#).
Complex chords map to closest OM types: 9→7/add9; 11/13→7; 6→maj; sus2→sus4; m9→m7; Maj9→Maj7/add9.
Related: relative major/minor and dominant (V) shown for quick substitution ideas.
New: "What next?" suggests likely next chords using I‑IV‑V, ii‑V‑I, and circle‑of‑fifths motion.

OM-108 combos: Maj7 = MAJ+7TH; m7 = MIN+7TH; Aug = MAJ+MIN+7TH; Dim = MAJ+MIN; Csus4 = C‑MAJ + F-7TH; Cadd9 = C-MAJ + F‑MIN.

Omnichord Chord helper · Halftone chord builder