Aphex Twin · Selected Ambient Works 85–92
Ptolemy
Ptolemy is in C sharp minor at 117.3 beats per minute.
Tempo
117 BPM · Moderatomedian of 127 analyses · 117.3–120.8 across the middle eight tenths- Key
- C♯ minor4 sharps · the key most of the analyses agreed on
- Agreement
- 98%share of analyses that agreed
- Analyses
- 127people who ran the extractor
- One beat
- 511.5milliseconds, 60,000 ÷ BPM
- Tuning
- 434.2Hz · -23 cents from A 440
- Dynamics
- 2.73dB the level wanders from its average
- Loudness
- 0.938Essentia's 0–1 scale, not dB
- Danceability
- 1.579Essentia'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
127 independent analyses of this recording were submitted to AcousticBrainz. All but a handful of them — 98% — put it in C sharp minor, a key signature of 4 sharps. The tempo printed above is the median of the 127 readings; 76% of them land within 2% of it, and the middle eight tenths of them run from 117.3 to 120.8 BPM.
At 117.3 BPM one beat lasts 511.5 milliseconds, so a sixteenth note is 127.9 ms and a dotted eighth 383.6 ms — the delay times for this recording. Counted half as fast it is 58.7 BPM, counted twice as fast 234.6. A score would mark that Moderato, 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 2.73 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 0.938 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 sharp 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 C♯ minor
Each of these differs from C♯ 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 117 BPM
| Note value | Beats | Milliseconds | Hertz |
|---|---|---|---|
| Whole note | 4 | 2046 | 0.49 |
| Half note | 2 | 1023 | 0.98 |
| Dotted quarter | 1.5 | 767.3 | 1.3 |
| Quarter note (one beat) | 1 | 511.5 | 1.96 |
| Quarter triplet | 0.667 | 341 | 2.93 |
| Dotted eighth | 0.75 | 383.6 | 2.61 |
| Eighth note | 0.5 | 255.8 | 3.91 |
| Eighth triplet | 0.333 | 170.5 | 5.87 |
| Dotted sixteenth | 0.375 | 191.8 | 5.21 |
| Sixteenth note | 0.25 | 127.9 | 7.82 |
| Sixteenth triplet | 0.167 | 85.3 | 11.73 |
| Thirty-second note | 0.125 | 63.9 | 15.64 |
Half time 58.7 BPM · double time 234.6 BPM. Every row is one beat (511.5 ms) times the fraction in the second column.
Closest in key and tempo
- EquinoxJohn ColtraneC♯ minor117BPM
- The Working ManCreedence Clearwater RevivalC♯ minor117BPM
- Face to FaceDaft PunkC♯ minor118BPM
- ThrillerMichael JacksonC♯ minor118BPM
- Representin’ 932PacC♯ minor119BPM
- It’s a MiracleCulture ClubC♯ minor119BPM
- Strike It UpBlack BoxC♯ minor119BPM
- ArrivalDaft PunkC♯ minor120BPM
- The BrainwasherDaft PunkC♯ minor120BPM
- MapsMaroon 5C♯ minor120BPM
Recordings in C sharp minor, ordered by how near their tempo is to 117 BPM. A calculation, not a recommendation.
All songs in C sharp minorAll songs at 117 BPMC♯ minor at 110–119 BPMAphex Twin
MusicBrainz collapses 1 recording id into this one. Recording id 3a028d7d-d5ba-40c7-9547-ba6af62a275a.