{"uid":"cap_T6rqnuVeo5JnamItvDpe_","slug":"saylor-innovations-music-key-finder-81ccd21f","name":"Saylor Innovations Music Key Finder","description":"Ranked candidate keys, out-of-key notes, modes and Roman numeral analysis","url":"https://saylorinnovations.com/api/music/key-finder?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","POST","PUT","PATCH","DELETE","HEAD"],"type":"string"},"queryParams":{"type":"object","properties":{"notes":{"type":"string","description":"optional notes separated by spaces, commas or dashes, with optional weights as note:count for example C:8 E:4 G:5 A:3 (query)"},"chords":{"type":"string","description":"optional chords such as C Am F G7 (query)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string","const":"json"},"example":{"type":"object"},"description":{"type":"string"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_wGcwXmhVpX2P9_JGccE5C","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Analyzes a set of notes or chords to return ranked candidate musical keys, out-of-key notes, modes, and Roman numeral chord analysis","exampleAgentPrompt":"What key are these notes in — C, E, G, A, and D — and can you also tell me which notes fall outside the top key and give me a Roman numeral analysis?","exampleUseCases":[{"title":"Identify key from a melody","prompt":"I've been playing around with the notes C, D, E, G, and A — can you figure out what key or mode that most likely belongs to, and flag any notes that seem out of key?"},{"title":"Chord progression key analysis","prompt":"I have a chord progression: C Am F G7 — what key is it in, what are the candidate keys ranked by fit, and can you show me the Roman numerals for each chord?"},{"title":"Weighted note key detection","prompt":"I've counted how often each note appears in my song: C appears 8 times, E 4 times, G 5 times, A 3 times — what's the most likely key, and are there any out-of-key notes?"}],"resultDescription":"Returns a ranked list of candidate musical keys with fit scores, identification of out-of-key notes, possible modes associated with the best-fit keys, and Roman numeral analysis of any chords provided relative to the detected key.","failureModes":["Missing both notes and chords parameters returns an error or empty result","Unrecognized note names or chord symbols may be ignored or cause a parse error","Very ambiguous note sets may return multiple equally-ranked keys with low confidence","Malformed weight syntax (e.g. C-8 instead of C:8) may be ignored silently"],"whenToPreferThis":"Choose this endpoint when you need music-theory-grounded key detection from a set of notes or chords, especially when you want ranked alternatives, modal identification, or Roman numeral harmonic analysis — rather than just a simple best-guess key name.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:42:22.212Z","isFirstParty":false,"canonicalSlug":"saylor-innovations-music-key-finder-81ccd21f"}