Tempo ↔ Milliseconds Converter

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Audio, Music, Photography & Color

Tranche

tranche-4

Evidence ID

t4-097

Ledger rows

1

No ledger note is attached.

Review findings

The implementation should document the note-value factor table and require BPM > 0. The empty honest_label is a concern: the user-facing label should explicitly state that BPM is quarter-note BPM and that note values are converted using factors relative to a quarter note.

Formula and scope findings

• The formula is standard only when BPM means quarter-note beats per minute and noteValueFactor is explicitly defined relative to one quarter note.
• The spec does not define the allowed note values or their factors, so “any note value” is ambiguous.
• The spec does not state whether BPM must be a positive number or how invalid and zero BPM inputs are handled.

Unit assumptions

• BPM is quarter-note beats per minute.
• 60000 is the number of milliseconds in one minute.
• noteValueFactor is dimensionless: quarter note = 1, half note = 2, whole note = 4, eighth note = 0.5, sixteenth note = 0.25, dotted quarter = 1.5, and so on.
• The output ms is milliseconds per specified note value.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The specification does not define input-domain rejection or note-value parsing. BPM = 0 is undefined, negative BPM yields an invalid negative duration, and the notation 1/4 can produce 125 ms or 2000 ms depending on convention.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "BPM": 120,
    "note_value": "quarter",
    "noteValueFactor": 1
  },
  "expected_outputs": {
    "ms": 500
  },
  "working": "60000 / 120 = 500 ms per quarter note; 500 × 1 = 500 ms."
}

Related workflows

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json