Frequency in Hz to the nearest note, MIDI number and offset in cents; adjustable
Frequency in Hz to the nearest note, MIDI number and offset in cents; adjustable A4 reference; tuner-style result.
Answeringour last check, 2026-10-21
1 of 1checks answered this week
1398 msmedian answer time
$0.02listed price per call
$0.02price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://music-theory.x402tookit.com/freq-note
| Category | Everything else |
|---|---|
| Provider host | music-theory.x402tookit.com |
| Networks | eip155:137, eip155:42161, eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-21 | valid payment request | 402 | $0.02 | 1398 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"hz": 442
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"a4": {
"description": "Reference pitch for A4 in Hz, 400 to 480 (default 440)",
"type": "number"
},
"accidentals": {
"description": "sharps (default) or flats for the note name",
"type": "string"
},
"hz": {
"description": "Frequency in Hz, 8 to 14000",
"type": "number"
}
},
"required": [
"hz"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"a4Hz": {
"type": [
"null",
"number"
]
},
"asOf": {
"type": [
"null",
"string"
]
},
"centsOffset": {
"type": [
"null",
"number"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"direction": {
"type": [
"null",
"string"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"fractionalMidi": {
"type": [
"null",
"number"
]
},
"frequencyHz": {
"type": [
"null",
"number"
]
},
"midi": {
"type": [
"null",
"number"
]
},
"nearestFrequencyHz": {
"type": [
"null",
"number"
]
},
"nearestNote": {
"type": [
"null",
"string"
]
},
"notChecked": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"reasons": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"source": {
"type": [
"null",
"string"
]
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}