{"uid":"cap_aL0YAdg0AkXr6oihgk1fu","slug":"music-openverbs-chord-builder-65d44263","name":"Music OpenVerbs Chord Builder","description":"Build a chord from a root note and quality (major, minor, dim, aug, maj7, min7, dom7, dim7, half-dim7, sus2, sus4, maj6, min6). Notes are spelled by stacked thirds (C dom7 → C E G Bb). Returns the note names, MIDI numbers and semitone intervals.","url":"https://music.openverbs.com/v1/chord","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["root","quality"],"properties":{"root":{"type":"string","maxLength":8,"minLength":1,"description":"Root note, e.g. \"C4\"."},"quality":{"enum":["major","minor","dim","aug","maj7","min7","dom7","dim7","half-dim7","sus2","sus4","maj6","min6"],"type":"string","description":"Chord quality."}},"additionalProperties":false},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_rHKRFsDNQRxW31wO3r1rS","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Builds a chord from a root note and quality, returning note names, MIDI numbers, and semitone intervals spelled by stacked thirds.","exampleAgentPrompt":"What notes, MIDI numbers, and intervals are in a C dominant 7th chord?","exampleUseCases":[{"title":"Chord fingering lookup for app","prompt":"I'm building a guitar app — what are all the notes and their MIDI numbers in a G major chord?"},{"title":"Music theory homework helper","prompt":"Can you spell out a B half-diminished 7 chord for me, showing the note names and how many semitones apart they are?"},{"title":"DAW MIDI composition aid","prompt":"I want to program a Bb minor 7 chord into my DAW — give me the MIDI note numbers for all the notes."}],"resultDescription":"Returns the chord's constituent note names (e.g. C, E, G, Bb), their corresponding MIDI numbers, and the semitone intervals between stacked thirds, all derived from the specified root note and chord quality.","failureModes":["Invalid root note format returns a validation error","Unsupported chord quality not in the enum returns a 400 error","Malformed request body missing required fields returns a schema validation error","Payment not included or insufficient USDC causes a 402 payment required response"],"whenToPreferThis":"Choose this endpoint when you need programmatic, theory-correct chord spellings including MIDI note numbers and semitone intervals — especially for music apps, DAW automation, music education tools, or any agent needing structured chord data rather than a plain text description.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T17:51:31.111Z","isFirstParty":false}