TempoPeek

Iron Maiden · The Number of the Beast

The Number of the Beast

The Number of the Beast is in D minor at 101.4 beats per minute.

4080120160200

Tempo

101 BPM · Andantemedian of 129 analyses · 100.6–101.6 across the middle eight tenths
Key
D minor1 flat · the key most of the analyses agreed on
Agreement
99%share of analyses that agreed
Analyses
129people who ran the extractor
One beat
591.7milliseconds, 60,000 ÷ BPM
Tuning
438.5Hz · -6 cents from A 440
Dynamics
4.68dB the level wanders from its average
Loudness
0.875Essentia's 0–1 scale, not dB
Danceability
1.271Essentia's danceability, 0–3

Source: AcousticBrainz, dump of 2022-06-23 (CC0) · MusicBrainz core data, 2026-09-17 (CC0) · how each number is measured. Measured up to 23.06.2022 — AcousticBrainz stopped collecting in 2022, so nothing released after that date is here.

What the numbers say

129 independent analyses of this recording were submitted to AcousticBrainz. All but a handful of them — 99% — put it in D minor, a key signature of 1 flat. The tempo printed above is the median of the 129 readings; 99% of them land within 2% of it, and they barely differ at all.

At 101.4 BPM one beat lasts 591.7 milliseconds, so a sixteenth note is 147.9 ms and a dotted eighth 443.8 ms — the delay times for this recording. Counted half as fast it is 50.7 BPM, counted twice as fast 202.8. A score would mark that Andante, by the ranges this site uses.

The analyses put the reference pitch of the recording at 438.5 Hz, which is 6 cents below concert A at 440 Hz — the sort of drift a tape machine or a slightly different mastering leaves behind. That is a fact about this transfer of the music, not about how it was played.

The dynamic complexity of the recording measures 4.68 dB: that is how far the level wanders from its own average, so a small number means a loud, flat master and a large one means a recording that still breathes. Its average loudness is 0.875 on Essentia's 0-to-1 scale, which is not decibels and is not comparable to a streaming service's number.

10 other recordings here are in D minor; the ones listed below are the closest in tempo.

Beats per bar are not in this dataset. AcousticBrainz's analysis reports a tempo, a key and a loudness, and no time signature at all, so this page does not print one — a 4/4 here would be a guess dressed as a measurement.

Keys that fit with D minor

Each of these differs from D minor by at most one accidental, or shares its tonic. That is the whole of what a mixing wheel encodes; here the relations are named instead of numbered.

Delay times at 101 BPM

Note valueBeatsMillisecondsHertz
Whole note42366.90.42
Half note21183.40.85
Dotted quarter1.5887.61.13
Quarter note (one beat)1591.71.69
Quarter triplet0.667394.52.54
Dotted eighth0.75443.82.25
Eighth note0.5295.93.38
Eighth triplet0.333197.25.07
Dotted sixteenth0.375221.94.51
Sixteenth note0.25147.96.76
Sixteenth triplet0.16798.610.14
Thirty-second note0.1257413.52

Half time 50.7 BPM · double time 202.8 BPM. Every row is one beat (591.7 ms) times the fraction in the second column.

Closest in key and tempo

  1. Song for a Future GenerationThe B‐52sD minor102BPM
  2. Saviour MachineDavid BowieD minor102BPM
  3. Heart and SoulJoy DivisionD minor101BPM
  4. Orange Juice Blues (Blues for Breakfast)Bob Dylan & The BandD minor102BPM
  5. Let Yourself GoGreen DayD minor101BPM
  6. Love, in ItselfDepeche ModeD minor101BPM
  7. Nobody Weird Like MeRed Hot Chili PeppersD minor101BPM
  8. Song of the CenturyGreen DayD minor101BPM
  9. Insane in the BrainCypress HillD minor102BPM
  10. (I Can’t Get No) SatisfactionDEVOD minor102BPM

Recordings in D minor, ordered by how near their tempo is to 101 BPM. A calculation, not a recommendation.

All songs in D minorAll songs at 101 BPMD minor at 100–109 BPMIron Maiden

MusicBrainz collapses 145 recording ids into this one. Recording id 8e44e4ea-9bce-47c2-a48c-8aa338242fb2.