Aphex Twin · Xylem Tube EP

Polynomial-C

Polynomial-C is in A flat major at 72.3 beats per minute.

Tempo

72 BPM · Adagiomedian of 133 analyses · 72.2–72.3 across the middle eight tenths

Key: A♭ major4 flats · the key most of the analyses agreed on
Agreement: 81%share of analyses that agreed
Analyses: 133people who ran the extractor
One beat: 829.9milliseconds, 60,000 ÷ BPM
Tuning: 452.1Hz · +47 cents from A 440
Dynamics: 3dB the level wanders from its average
Loudness: 0.867Essentia's 0–1 scale, not dB
Danceability: 1.379Essentia'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

133 independent analyses of this recording were submitted to AcousticBrainz. Most of them — 81% — put it in A flat major, a key signature of 4 flats. The tempo printed above is the median of the 133 readings; 100% of them land within 2% of it, and they barely differ at all.

At 72.3 BPM one beat lasts 829.9 milliseconds, so a sixteenth note is 207.5 ms and a dotted eighth 622.4 ms — the delay times for this recording. Counted half as fast it is 36.2 BPM, counted twice as fast 144.6. A score would mark that Adagio, by the ranges this site uses.

The analyses put the reference pitch of the recording at 452.1 Hz, which is 47 cents above concert A at 440 Hz — far enough that playing along at 440 Hz will sound wrong. That is a fact about this transfer of the music, not about how it was played.

The dynamic complexity of the recording measures 3 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 0.867 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 flat 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 72 BPM

Note value	Beats	Milliseconds	Hertz
Whole note	4	3319.5	0.3
Half note	2	1659.8	0.6
Dotted quarter	1.5	1244.8	0.8
Quarter note (one beat)	1	829.9	1.21
Quarter triplet	0.667	553.3	1.81
Dotted eighth	0.75	622.4	1.61
Eighth note	0.5	414.9	2.41
Eighth triplet	0.333	276.6	3.62
Dotted sixteenth	0.375	311.2	3.21
Sixteenth note	0.25	207.5	4.82
Sixteenth triplet	0.167	138.3	7.23
Thirty-second note	0.125	103.7	9.64

Half time 36.2 BPM · double time 144.6 BPM. Every row is one beat (829.9 ms) times the fraction in the second column.

Closest in key and tempo

Recordings in A flat major, ordered by how near their tempo is to 72 BPM. A calculation, not a recommendation.

All songs in A flat major Aphex Twin

MusicBrainz collapses 3 recording ids into this one. Recording id 6643e2a6-a4b9-4ed8-8d50-c6864eba7c5f.