Sigur Rós · Ágætis byrjun
Intro
Intro is in C major at 128.5 beats per minute.
Tempo
129 BPM · Allegromedian of 131 analyses · 128.2–129.2 across the middle eight tenths- Key
- C majorno sharps and no flats · the key most of the analyses agreed on
- Agreement
- 99%share of analyses that agreed
- Analyses
- 131people who ran the extractor
- One beat
- 466.9milliseconds, 60,000 ÷ BPM
- Tuning
- 434.2Hz · -23 cents from A 440
- Dynamics
- 3.98dB the level wanders from its average
- Loudness
- 0.742Essentia's 0–1 scale, not dB
- Danceability
- 0.961Essentia'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
131 independent analyses of this recording were submitted to AcousticBrainz. All but a handful of them — 99% — put it in C major, a key signature of no sharps and no flats. The tempo printed above is the median of the 131 readings; 99% of them land within 2% of it, and they barely differ at all.
At 128.5 BPM one beat lasts 466.9 milliseconds, so a sixteenth note is 116.7 ms and a dotted eighth 350.2 ms — the delay times for this recording. Counted half as fast it is 64.3 BPM, counted twice as fast 257. A score would mark that Allegro, by the ranges this site uses.
The analyses put the reference pitch of the recording at 434.2 Hz, which is 23 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 3.98 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 0.742 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 C 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 C major
Each of these differs from C 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 129 BPM
| Note value | Beats | Milliseconds | Hertz |
|---|---|---|---|
| Whole note | 4 | 1867.7 | 0.54 |
| Half note | 2 | 933.9 | 1.07 |
| Dotted quarter | 1.5 | 700.4 | 1.43 |
| Quarter note (one beat) | 1 | 466.9 | 2.14 |
| Quarter triplet | 0.667 | 311.3 | 3.21 |
| Dotted eighth | 0.75 | 350.2 | 2.86 |
| Eighth note | 0.5 | 233.5 | 4.28 |
| Eighth triplet | 0.333 | 155.6 | 6.43 |
| Dotted sixteenth | 0.375 | 175.1 | 5.71 |
| Sixteenth note | 0.25 | 116.7 | 8.57 |
| Sixteenth triplet | 0.167 | 77.8 | 12.85 |
| Thirty-second note | 0.125 | 58.4 | 17.13 |
Half time 64.3 BPM · double time 257 BPM. Every row is one beat (466.9 ms) times the fraction in the second column.
The same title by somebody else
- IntroBackstreet BoysG♯ minor172BPM
- IntroAerosmithB♭ minor123BPM
- Intro2PacB♭ minor162BPM
- IntroChromeoF minor133BPM
- IntroGorillazF minor134BPM
- Intro50 CentE♭ major85BPM
- IntroThe ProdigyC major128BPM
Matched on the title alone, so this list can hold a different song that happens to share a name. Nothing here claims one is a cover of the other.
Closest in key and tempo
- Brown SugarThe Rolling StonesC major129BPM
- Come Around AgainJetC major129BPM
- JacksonJohnny Cash & June CarterC major129BPM
- All or Nothing At AllFrank SinatraC major128BPM
- Star Me KittenR.E.M.C major129BPM
- You Can't Do ThatThe BeatlesC major129BPM
- Seven YearsNorah JonesC major128BPM
- Cripple Creek FerryNeil YoungC major128BPM
- Just Can’t Get EnoughDepeche ModeC major128BPM
- Love Is Reasona‐haC major129BPM
Recordings in C major, ordered by how near their tempo is to 129 BPM. A calculation, not a recommendation.
All songs in C majorAll songs at 129 BPMC major at 120–129 BPM
MusicBrainz collapses 3 recording ids into this one. Recording id 80c8836e-5dff-4d00-a092-8094216921f3.