Identify chord from notes API

Identifies the chord(s) implied by a set of notes, testing every note as a possible root (inversions) against a recipe table and returning the root-position best match. Answers 'What chord is C-E-G?', 'Name the chord A-C-E.'.

Price$0.06per request

MethodPOST

Route/v1/music/chord-identify

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

musicchordidentifyrecognitionharmonyinversiontheorynotesaudio

API URLhttps://x402.hexl.dev/v1/music/chord-identify

Integration docs

Example request

{
  "notes": [
    "C4",
    "E4",
    "G4"
  ]
}

Example response

{
  "inputNotes": [
    "C4",
    "E4",
    "G4"
  ],
  "pitchClasses": [
    0,
    4,
    7
  ],
  "pitchClassNames": [
    "C",
    "E",
    "G"
  ],
  "matchCount": 1,
  "matches": [
    {
      "root": "C",
      "quality": "maj",
      "name": "C",
      "fullName": "C major triad",
      "rootPosition": true
    }
  ],
  "bestMatch": {
    "root": "C",
    "quality": "maj",
    "name": "C",
    "fullName": "C major triad",
    "rootPosition": true
  },
  "identified": true
}

Input schema

{
  "type": "object",
  "required": [
    "notes"
  ],
  "properties": {
    "notes": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "examples": [
        [
          "C4",
          "E4",
          "G4"
        ]
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}