{"uid":"cap_BnCXY2k4W42Ot19SSrBlt","slug":"music-production-calc-key-shift-e269a6eb","name":"Music Production Calc: Key Shift","description":"Shift a key by semitones with the right sharp or flat spelling, its relative major or minor, signature and capo shapes.","url":"https://music-production-calc.x402tookit.com/key-shift?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","semitones"],"properties":{"key":{"type":"string","description":"Starting key: C, F#, Bb, Am, F#m or 'Bb minor' (no mode means major)"},"capo":{"type":"integer","description":"Capo fret 1 to 11 to get the chord-shape key to play (optional)"},"prefer":{"type":"string","description":"sharps or flats, used only when two spellings are equally simple (for example F# or Gb major)"},"semitones":{"type":"integer","description":"Shift in semitones, -24 to 24 (positive is up)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"toKey":{"type":["null","string"]},"source":{"type":["null","string"]},"toMode":{"type":["null","string"]},"fromKey":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"capoChoice":{},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"capoOptions":{"type":["array","null"],"items":{"type":"object","properties":{"capo":{"type":["null","number"]},"shapeKey":{"type":["null","string"]},"signature":{"type":["null","string"]},"openFriendly":{"type":["boolean","null"]}}}},"relativeKey":{"type":["null","string"]},"toSignature":{"type":["null","string"]},"fromSignature":{"type":["null","string"]},"fromRelativeKey":{"type":["null","string"]},"semitonesShifted":{"type":["null","number"]},"toFifthsPosition":{"type":["null","number"]}}}}}}},"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_eETcVe7OP_wSUTyUOncDL","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":"Shifts a musical key by a given number of semitones, returning the correctly spelled destination key, its mode, relative key, key signature, and capo chord shapes.","exampleAgentPrompt":"I'm playing a song in F# major and need to transpose it up 3 semitones — can you tell me the resulting key with the correct sharp or flat spelling, its key signature, relative minor, and capo shapes if I'm using a capo?","exampleUseCases":[{"title":"Transpose song for vocalist range","prompt":"The song is in Bb major but my vocalist needs it 2 semitones higher — what key does that land in, is it sharp or flat, and what's the key signature?"},{"title":"Capo chord shapes after key shift","prompt":"I want to play a song that's in E major but shift it down 2 semitones to D major — what capo fret and chord shapes would I use on guitar to keep open-friendly fingering?"},{"title":"Find relative key after transposition","prompt":"If I take a song in C# minor and shift it up 4 semitones, what's the new key and what is its relative major? Use sharps if there's a tie."}],"resultDescription":"Returns the destination key name with correct sharp or flat spelling, mode (major/minor), relative key, key signature (e.g. '3 sharps'), number of semitones shifted, fifths position, and an array of capo options each with fret number, chord-shape key, key signature, and open-friendly flag.","failureModes":["Invalid key string format returns an error (e.g. unrecognized key name)","Semitones outside -24 to 24 range rejected","Capo fret outside 1–11 range rejected","Missing required query parameters (key or semitones) returns 400-level error"],"whenToPreferThis":"Use this endpoint when you need musically correct transposition with proper enharmonic spelling (e.g. F# vs Gb), key signature, relative key, and guitar capo chord shapes — rather than a simple chromatic lookup table or a generic music theory library that may not handle enharmonic spelling or capo logic.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-11-03T12:30:47.645Z","isFirstParty":false,"canonicalSlug":"music-production-calc-key-shift-e269a6eb"}