# music.openverbs.com Transpose Note

> music.openverbs.com Transpose Note is a paid API for AI agents from music.openverbs.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-15).

Transposes a musical note up or down by a specified number of semitones, returning the result spelled with sharps or flats.

## Facts

- Endpoint: POST https://music.openverbs.com/v1/transpose
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/music-openverbs-com-transpose-note-679a0c1f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_887ogNfc1sDBfvRKBeToB

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability music-openverbs-com-transpose-note-679a0c1f -d '<json body>'
```

Example prompt: What note is 7 semitones above F#? Spell the result with sharps.

## When to prefer this

Use this endpoint when you need to computationally shift a single note by an exact number of semitones and get the resulting note name back — especially when you need control over accidental spelling (sharps vs flats). Prefer this over manual calculation or a full scale/chord builder when the task is purely a single-note transposition.

## Known failure modes

- Note string is empty or missing — validation error
- Semitones value outside -127 to 127 range — validation error
- Note string is not a recognized note name — parse error
- preferFlats is not a boolean — type error
- Missing required fields (note or semitones) — 400 bad request

## How this service works

Transpose a note by a (possibly negative) number of semitones. Result is spelled chromatically with sharps, or flats when `preferFlats` is true.

## Output

Returns the transposed note name as a string, spelled chromatically using sharps by default (e.g. 'C#', 'F#') or flats when preferFlats is true (e.g. 'Db', 'Gb').

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "note",
      "semitones"
     ],
     "properties": {
      "note": {
       "type": "string",
       "maxLength": 8,
       "minLength": 1,
       "description": "Note to transpose."
      },
      "semitones": {
       "type": "integer",
       "maximum": 127,
       "minimum": -127,
       "description": "Semitones to move (negative = down)."
      },
      "preferFlats": {
       "type": "boolean",
       "description": "Spell the result with flats. Default false (sharps)."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/music-openverbs-com-transpose-note-679a0c1f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from music.openverbs.com](https://www.zero.xyz/host/music.openverbs.com/llms.txt)