# Music Scale Builder

> Music Scale Builder is a paid API for AI agents from music.openverbs.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Builds a musical scale from a root note and scale type, returning note names, MIDI numbers, and semitone intervals

## Facts

- Endpoint: POST https://music.openverbs.com/v1/scale
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/music-scale-builder-64d54864
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hiWVZt-GpJpo8QlJnUow_

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-scale-builder-64d54864 -d '<json body>'
```

Example prompt: Give me all the notes in a G major-pentatonic scale starting from G4, including their MIDI numbers and semitone intervals.

## When to prefer this

Use this endpoint when you need structured music-theory data — note names, MIDI values, and intervals — for any standard Western scale or mode. Prefer it over generic music-generation endpoints when you need diatonically correct spelling (e.g. F major returns Bb not A#) or precise MIDI numbers for programmatic use in sequencers, DAWs, or music-theory applications.

## Known failure modes

- Invalid root note format returns an error (e.g. missing octave number or malformed accidental)
- Unrecognized scale type enum value returns a validation error
- Missing required fields (root or type) returns a 400-level error
- Payment failure via x402 protocol blocks the request

## How this service works

Build a scale from a root note and type (major, natural-minor, harmonic-minor, melodic-minor, dorian, phrygian, lydian, mixolydian, locrian, major-pentatonic, minor-pentatonic, blues, chromatic). Heptatonic scales and modes are spelled diatonically (F major → F G A Bb C D E). Returns the note names, MIDI numbers and semitone intervals.

## Output

Returns the complete list of note names (spelled diatonically where applicable, e.g. Bb not A#), their corresponding MIDI note numbers, and the semitone intervals between consecutive scale degrees.

## Request schema (JSON Schema)

```json
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string",
     "enum": [
      "POST"
     ]
    },
    "bodyType": {
     "type": "string",
     "enum": [
      "json",
      "form-data",
      "text"
     ]
    },
    "body": {
     "type": "object",
     "properties": {
      "root": {
       "type": "string",
       "minLength": 1,
       "maxLength": 8,
       "description": "Root note, e.g. \"C4\"."
      },
      "type": {
       "type": "string",
       "enum": [
        "major",
        "natural-minor",
        "harmonic-minor",
        "melodic-minor",
        "dorian",
        "phrygian",
        "lydian",
        "mixolydian",
        "locrian",
        "major-pentatonic",
        "minor-pentatonic",
        "blues",
        "chromatic"
       ],
       "description": "Scale type."
      }
     },
     "required": [
      "root",
      "type"
     ],
     "additionalProperties": false
    }
   },
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "additionalProperties": false
  }
 },
 "required": [
  "input"
 ]
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/music-scale-builder-64d54864/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)