TempoPeek

Black Sabbath · Paranoid

Iron Man

Iron Man is in A major at 154.7 beats per minute.

4080120160200

Tempo

155 BPM · Allegromedian of 392 analyses · 154.6–154.8 across the middle eight tenths
Key
A major3 sharps · the key most of the analyses agreed on
Agreement
94%share of analyses that agreed
Analyses
392people who ran the extractor
One beat
387.8milliseconds, 60,000 ÷ BPM
Tuning
447.9Hz · +31 cents from A 440
Dynamics
2.78dB the level wanders from its average
Loudness
0.876Essentia's 0–1 scale, not dB
Danceability
1.178Essentia'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

392 independent analyses of this recording were submitted to AcousticBrainz. Most of them — 94% — put it in A major, a key signature of 3 sharps. The tempo printed above is the median of the 392 readings; 95% of them land within 2% of it, and they barely differ at all.

At 154.7 BPM one beat lasts 387.8 milliseconds, so a sixteenth note is 97 ms and a dotted eighth 290.9 ms — the delay times for this recording. Counted half as fast it is 77.4 BPM, counted twice as fast 309.4. A score would mark that Allegro, by the ranges this site uses.

The analyses put the reference pitch of the recording at 447.9 Hz, which is 31 cents above 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 2.78 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 0.876 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 A major; 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 A major

Each of these differs from A major 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 155 BPM

Note valueBeatsMillisecondsHertz
Whole note41551.40.64
Half note2775.71.29
Dotted quarter1.5581.81.72
Quarter note (one beat)1387.82.58
Quarter triplet0.667258.63.87
Dotted eighth0.75290.93.44
Eighth note0.5193.95.16
Eighth triplet0.333129.37.74
Dotted sixteenth0.375145.46.88
Sixteenth note0.259710.31
Sixteenth triplet0.16764.615.47
Thirty-second note0.12548.520.63

Half time 77.4 BPM · double time 309.4 BPM. Every row is one beat (387.8 ms) times the fraction in the second column.

Closest in key and tempo

  1. There’s No Home for You HereThe White StripesA major155BPM
  2. All the TimeGreen DayA major155BPM
  3. Fistful of SteelRage Against the MachineA major155BPM
  4. In God’s HandsNelly FurtadoA major155BPM
  5. SpitMeat PuppetsA major155BPM
  6. The Name of the GameABBAA major154BPM
  7. Another Rainy Day in New York CityChicagoA major154BPM
  8. Radio Free EuropeR.E.M.A major155BPM
  9. My HeroFoo FightersA major154BPM
  10. Breaking BreadJohnny CashA major155BPM

Recordings in A major, ordered by how near their tempo is to 155 BPM. A calculation, not a recommendation.

All songs in A majorAll songs at 155 BPMA major at 150–159 BPMBlack Sabbath

MusicBrainz collapses 135 recording ids into this one. Recording id a15e2d0a-efcb-4f4f-ad54-22a4879bbcf9.