{"uid":"cap_pylQA3I41VPuO38q_1Sbj","slug":"music-production-calc-diatonic-chords-ea3fbcfc","name":"Music Production Calc – Diatonic Chords","description":"The 7 triads and 7th chords of a key (major, natural or harmonic minor) with spelled notes and Roman numerals.","url":"https://music-production-calc.x402tookit.com/diatonic-chords?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["key"],"properties":{"key":{"type":"string","description":"Key: C, F#, Bb, Am, F#m or 'Bb minor' (no mode means major)"},"scale":{"type":"string","description":"major, minor (natural) or harmonic-minor; default follows the key's mode"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"key":{"type":["null","string"]},"asOf":{"type":["null","string"]},"chords":{"type":["array","null"],"items":{"type":"object","properties":{"roman":{"type":["null","string"]},"triad":{"type":["null","string"]},"degree":{"type":["null","number"]},"seventh":{"type":["null","string"]},"triadNotes":{"type":["array","null"],"items":{"type":"string"}},"seventhNotes":{"type":["array","null"],"items":{"type":"string"}},"triadQuality":{"type":["null","string"]}}}},"source":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"scaleUsed":{"type":["null","string"]},"signature":{"type":["null","string"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"scaleNotes":{"type":["array","null"],"items":{"type":"string"}}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_yR7tpomfQ84IarjdwgaAD","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns all 7 diatonic triads and 7th chords for a given key (major, natural minor, or harmonic minor) with spelled notes, Roman numerals, and chord qualities.","exampleAgentPrompt":"What are all the diatonic triads and 7th chords in the key of F# minor (harmonic minor)? Give me the Roman numerals and the spelled-out notes for each chord.","exampleUseCases":[{"title":"Chord chart for a new song key","prompt":"I'm writing a song in Bb major — can you show me all 7 diatonic triads and 7th chords with their Roman numerals and the actual note names in each chord?"},{"title":"Harmonic minor chord analysis","prompt":"What are the diatonic chords in A harmonic minor? I need the triad and 7th chord spellings and their Roman numerals for each scale degree."},{"title":"Identifying chord qualities for production","prompt":"List all the triads and 7th chords for the key of Eb major, including the quality of each chord (major, minor, diminished, etc.) and which notes are in them."}],"resultDescription":"A structured list of 7 diatonic chord entries, each containing: scale degree number, Roman numeral (e.g. IIm7, V7, viidim7), triad name, seventh chord name, triad quality, triad notes array, seventh chord notes array, plus the scale notes used and the resolved scale type (major, natural minor, or harmonic minor).","failureModes":["Missing or unrecognized key parameter returns an error or null chords","Ambiguous key notation (e.g. both 'Am' and 'A minor' should work, but malformed strings may fail)","Unsupported scale type string returns default or error","Network timeout or payment failure returns no data"],"whenToPreferThis":"Use this endpoint when you need the full set of diatonic chords for a key with precise note spelling, Roman numeral analysis, and chord quality labels — particularly useful for music theory lookups, chord progression generation, DAW session planning, or educational music tools. Prefer it over manual calculation when working with non-standard keys (e.g. Bb, F#, enharmonic spellings) or harmonic minor scale variants.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T13:13:47.386Z","isFirstParty":false,"canonicalSlug":"music-production-calc-diatonic-chords-ea3fbcfc"}