TempoPeek

Keri Hilson feat. Kanye West & Ne‐Yo · In a Perfect World...

Knock You Down

Knock You Down is in B flat major at 155 beats per minute.

4080120160200

Tempo

155 BPM · Allegromedian of 132 analyses · 155–155 across the middle eight tenths
Key
B♭ major2 flats · the key most of the analyses agreed on
Agreement
100%share of analyses that agreed
Analyses
132people who ran the extractor
One beat
387.1milliseconds, 60,000 ÷ BPM
Tuning
434.2Hz · -23 cents from A 440
Dynamics
3.51dB the level wanders from its average
Loudness
0.8Essentia's 0–1 scale, not dB
Danceability
1.426Essentia'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

132 independent analyses of this recording were submitted to AcousticBrainz. All but a handful of them — 100% — put it in B flat major, a key signature of 2 flats. The tempo printed above is the median of the 132 readings; 100% of them land within 2% of it, and they barely differ at all.

At 155 BPM one beat lasts 387.1 milliseconds, so a sixteenth note is 96.8 ms and a dotted eighth 290.3 ms — the delay times for this recording. Counted half as fast it is 77.5 BPM, counted twice as fast 310. 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 3.51 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 0.8 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 B 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 B♭ major

Each of these differs from B♭ 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 note41548.40.65
Half note2774.21.29
Dotted quarter1.5580.61.72
Quarter note (one beat)1387.12.58
Quarter triplet0.667258.13.88
Dotted eighth0.75290.33.44
Eighth note0.5193.55.17
Eighth triplet0.3331297.75
Dotted sixteenth0.375145.26.89
Sixteenth note0.2596.810.33
Sixteenth triplet0.16764.515.5
Thirty-second note0.12548.420.67

Half time 77.5 BPM · double time 310 BPM. Every row is one beat (387.1 ms) times the fraction in the second column.

Closest in key and tempo

  1. Shit on the Radio (Remember the Days)Nelly FurtadoB♭ major155BPM
  2. Bridge Over Troubled WaterAretha FranklinB♭ major155BPM
  3. In BloomNirvanaB♭ major155BPM
  4. Promises in the DarkPat BenatarB♭ major156BPM
  5. That’s How Strong My Love IsOtis ReddingB♭ major156BPM
  6. Meant to BeBebe Rexha feat. Florida Georgia LineB♭ major154BPM
  7. Marshmallow WorldDarlene LoveB♭ major154BPM
  8. The Lady in RedChris de BurghB♭ major154BPM
  9. Make You Feel My LoveAdeleB♭ major153BPM
  10. Miss MeDrake feat. Lil WayneB♭ major153BPM

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

All songs in B flat majorAll songs at 155 BPMB♭ major at 150–159 BPM

MusicBrainz collapses 5 recording ids into this one. Recording id 4dab0d4f-2992-4140-8d08-1a364a6d4957.