# Music Theory Tempo Calculator

> Music Theory Tempo Calculator 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 BPM tempo into delay times and note durations in milliseconds, or averages tap intervals into a steady BPM value.

## Facts

- Endpoint: GET https://music-theory.x402tookit.com/tempo?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/music-theory-tempo-calculator-f7fd0089
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_t-n9K2AglhCCINSEz92_s

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-theory-tempo-calculator-f7fd0089
```

Example prompt: What are the delay times in milliseconds for all note values — including dotted and triplet — at 120 BPM with 4 beats per bar?

## When to prefer this

Use this endpoint when you need precise millisecond timings for delay effects, DAW grid alignment, or rhythmic synchronization derived from a BPM value, or when you need to convert tap-tempo intervals into a stable BPM. It is the right choice over general music knowledge when you need computed numeric output ready to plug into audio hardware or software.

## Known failure modes

- BPM out of range (must be 20–400) returns validation error
- Fewer than two tap intervals provided returns insufficient data error
- Non-numeric or malformed tap interval string returns parse error
- beatsPerBar outside 1–16 range returns validation error

## How this service works

BPM to milliseconds for note values, dotted and triplet delay times; or average tap intervals into a steady BPM.

## Output

Returns the BPM (either as provided or averaged from taps), quarter note duration in ms, bar length in ms, and a full table of note values (whole, half, quarter, eighth, sixteenth, etc.) each with straight, dotted, and triplet millisecond durations, plus common delay time shortcuts (quarter, eighth, sixteenth, dotted eighth, eighth triplet). Also includes a summary string and any degraded-mode warnings.

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "bpm": {
       "type": "number",
       "description": "Tempo in beats per minute, 20 to 400 (quarter note = one beat)"
      },
      "taps": {
       "type": "string",
       "description": "Tap intervals in milliseconds, comma separated: 500,512,497,505 (use instead of bpm)"
      },
      "beatsPerBar": {
       "type": "integer",
       "description": "Beats per bar for the bar length, 1 to 16 (default 4)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "bpm": {
       "type": [
        "null",
        "number"
       ]
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "barMs": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "delayTimes": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "note": {
         "type": [
          "null",
          "string"
         ]
        },
        "eighth": {
         "type": [
          "null",
          "number"
         ]
        },
        "quarter": {
         "type": [
          "null",
          "number"
         ]
        },
        "sixteenth": {
         "type": [
          "null",
          "number"
         ]
        },
        "dottedEighth": {
         "type": [
          "null",
          "number"
         ]
        },
        "eighthTrip
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/music-theory-tempo-calculator-f7fd0089/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from music-theory.x402tookit.com](https://www.zero.xyz/host/music-theory.x402tookit.com/llms.txt)