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Music Theory Note-to-Frequency Converter
x402
Music Theory Note-to-Frequency Converter is a paid API for AI agents from music-theory.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).
Converts a note name (e.g. C#4, Bb3) or MIDI number to its MIDI value, frequency in Hz, and wavelength in cm, with an adjustable A4 reference pitch.
Price / call$0.02
Success—
StatusUnknown
How this service works
Note name (C#4, Bb3) or MIDI number to MIDI, frequency in Hz and wavelength, with adjustable A4 reference pitch.
Output
Returns the note name, MIDI number, pitch class, frequency in Hz, wavelength in cm, enharmonic equivalents, the A4 reference Hz used, and the octave convention, along with a summary and optional degraded/disclaimer flags.
Example use cases
Synthesizer patch frequency lookup
“I'm programming a synth patch and need the exact frequency in Hz and MIDI number for Bb3 using standard 440 Hz tuning — can you look that up?”
Baroque tuning instrument check
“What's the frequency and wavelength of A4 when the reference pitch is set to baroque tuning at 415 Hz?”
MIDI number to note properties
“I have MIDI note 60 — can you tell me the note name, frequency in Hz, and wavelength at standard 440 A4 tuning?”
Technical details
Endpoint
GEThttps://music-theory.x402tookit.com/note-freq?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to convert a note name or MIDI number to its exact frequency, MIDI value, and wavelength — especially when non-standard tuning (baroque 415, Verdi 432, custom A4) is required. Prefer this over generic music APIs when precise acoustic properties and enharmonic spellings are needed for a specific note.
Side effects
- Invalid note name format (e.g. missing octave number) returns an error
- MIDI number outside 0–127 range is rejected
- A4 reference pitch outside 400–480 Hz range is invalid
- Malformed query parameter causes a bad request response
- Missing required 'note' parameter returns an error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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