BPM detection consistently offset by -1 bpm

[fhill2]

Thank you for this great software.

I've been testing out DeepRhythm on some music files and comparing the results with the BPM values output from the Spotify Audio Analysis API

I haven't detected the BPM for these songs manually, however given the genre and the spotify audio analysis results, the actual BPMs are 174 (or 87), with some outliers -2 to +2.

The DeepRhythm results show most tracks at 86BPM instead, so it seems as though DeepRhythm audio analysis is consistently off by -1 bpm (or -2 BPM if we're double time).

Here are the results:

DeepRhythm vs Spotify Audio Analysis Results

ACRAZE -  Do It To It (Sub Focus Remix)
spotify bpm: 174
deeprhythm confidence: 0.953618049621582
deeprhythm bpm: 86.0
==========
Dimension -  Sensory Division
spotify bpm: 174
deeprhythm confidence: 0.7103237509727478
deeprhythm bpm: 86.0
==========
Marlon Hoffstadt -  It's That Time (Dimension Remix)
spotify bpm: 174
deeprhythm confidence: 0.9393355846405029
deeprhythm bpm: 86.0
==========
Prospa -  WANT NEED LOVE (Dimension Remix)
spotify bpm: 174
deeprhythm confidence: 0.7498885989189148
deeprhythm bpm: 86.0
==========
Changing Faces -  Rave Machine
spotify bpm: 174
deeprhythm confidence: 0.8920833468437195
deeprhythm bpm: 86.0
==========
Sub Focus -  Wildfire
spotify bpm: 174
deeprhythm confidence: 0.8396831154823303
deeprhythm bpm: 86.0
==========
Alok -  Jungle (Arcando Remix)
spotify bpm: 170
deeprhythm confidence: 0.8670021295547485
deeprhythm bpm: 84.0
==========
Culture Shock -  Renaissance (Edit)
spotify bpm: 174
deeprhythm confidence: 0.8943854570388794
deeprhythm bpm: 86.0
==========
CamelPhat -  Easier (feat. LOWES) (Sub Focus Remix)
spotify bpm: 174
deeprhythm confidence: 0.6655175089836121
deeprhythm bpm: 86.0
==========
Sub Focus -  Solar System
spotify bpm: 174
deeprhythm confidence: 0.8567098379135132
deeprhythm bpm: 86.0
==========
Dimension -  Remedy (feat. TS Graye)
spotify bpm: 174
deeprhythm confidence: 0.812551736831665
deeprhythm bpm: 86.0
==========
Turno -  Rave Out
spotify bpm: 87
deeprhythm confidence: 0.8659723401069641
deeprhythm bpm: 86.0
==========
Sub Focus -  Overcome
spotify bpm: 174
deeprhythm confidence: 0.6866841316223145
deeprhythm bpm: 86.0
==========
Dimension -  Alive (feat. Poppy Baskcomb)
spotify bpm: 174
deeprhythm confidence: 0.7765641808509827
deeprhythm bpm: 86.0
==========
Wilkinson -  Break It Down (feat. Emily Makis)
spotify bpm: 87
deeprhythm confidence: 0.7957808971405029
deeprhythm bpm: 86.0
==========
Robin Schulz -  One By One (feat. Oaks) (Andromedik Remix)
spotify bpm: 174
deeprhythm confidence: 0.705945611000061
deeprhythm bpm: 86.0
==========
Chase & Status -  Baddadan
spotify bpm: 88
deeprhythm confidence: 0.6676128506660461
deeprhythm bpm: 87.0
==========
Sub Focus -  It's Time
spotify bpm: 174
deeprhythm confidence: 0.9742075800895691
deeprhythm bpm: 86.0
==========
Wilkinson -  All For You
spotify bpm: 174
deeprhythm confidence: 0.6398037075996399
deeprhythm bpm: 86.0
==========
Bru-C -  Streetside
spotify bpm: 88
deeprhythm confidence: 0.844027042388916
deeprhythm bpm: 87.0
==========
Dimension -  Danger (feat. MC GQ)
spotify bpm: 174
deeprhythm confidence: 0.7941222190856934
deeprhythm bpm: 86.0
==========
Sub Focus -  Calling For A Sign
spotify bpm: 174
deeprhythm confidence: 0.8773098587989807
deeprhythm bpm: 86.0
==========
Sub Focus -  Air I Breathe (Sub Focus & Wilkinson)
spotify bpm: 174
deeprhythm confidence: 0.7093557119369507
deeprhythm bpm: 86.0
==========
Sub Focus -  I Found You
spotify bpm: 174
deeprhythm confidence: 0.7741753458976746
deeprhythm bpm: 86.0
==========
Culture Shock -  Breathe
spotify bpm: 174
deeprhythm confidence: 0.7205880284309387
deeprhythm bpm: 86.0
==========
Wilkinson -  Balance
spotify bpm: 174
deeprhythm confidence: 0.7379316091537476
deeprhythm bpm: 86.0
==========
Arcando -  Don't Tell Me
spotify bpm: 175
deeprhythm confidence: 0.7993200421333313
deeprhythm bpm: 87.0
==========
Hedex -  MHITR (Semi-Automatic) [feat. Eksman]
spotify bpm: 88
deeprhythm confidence: 0.6178063750267029
deeprhythm bpm: 87.0
==========
Slay -  Kenny
spotify bpm: 87
deeprhythm confidence: 0.8102020621299744
deeprhythm bpm: 87.0
==========
Wilkinson -  This Moment
spotify bpm: 174
deeprhythm confidence: 0.8703876733779907
deeprhythm bpm: 86.0
==========
John Summit -  Go Back
spotify bpm: 174
deeprhythm confidence: 0.3602178990840912
deeprhythm bpm: 86.0
==========
Arcando -  Mr. Brightside
spotify bpm: 174
deeprhythm confidence: 0.8602685928344727
deeprhythm bpm: 86.0
==========
deadmau5 -  Strobe (Dimension Remix)
spotify bpm: 174
deeprhythm confidence: 0.7336056232452393
deeprhythm bpm: 86.0
==========
Dimension -  Devotion (feat. Cameron Hayes)
spotify bpm: 174
deeprhythm confidence: 0.7153251767158508
deeprhythm bpm: 86.0
==========
Culture Shock -  Get To Me
spotify bpm: 174
deeprhythm confidence: 0.7477383017539978
deeprhythm bpm: 86.0
==========
D.O.D -  So Much In Love (Sub Focus Remix)
spotify bpm: 175
deeprhythm confidence: 0.6677268147468567
deeprhythm bpm: 87.0
==========
Switch Disco -  REACT (feat. Ella Henderson) (Culture Shock Remix)
spotify bpm: 174
deeprhythm confidence: 0.6971049308776855
deeprhythm bpm: 86.0
==========
AuRa -  Panic Room (Culture Shock Remix)
spotify bpm: 174
deeprhythm confidence: 0.8385540246963501
deeprhythm bpm: 86.0
==========
Dimension -  Hatred (feat. E11E)
spotify bpm: 174
deeprhythm confidence: 0.8025137782096863
deeprhythm bpm: 86.0
==========
MK -  Rhyme Dust (Dimension Remix)
spotify bpm: 174
deeprhythm confidence: 0.9129189848899841
deeprhythm bpm: 86.0
==========
Culture Shock -  There for You
spotify bpm: 174
deeprhythm confidence: 0.6764269471168518
deeprhythm bpm: 86.0
==========
T & Sugah -  Lose Control (feat. Grace Barton)
spotify bpm: 174
deeprhythm confidence: 0.8281576633453369
deeprhythm bpm: 86.0
==========
Loboski -  Keep On
spotify bpm: 174
deeprhythm confidence: 0.9348411560058594
deeprhythm bpm: 86.0
==========
Dimension -  Whip Slap II
spotify bpm: 174
deeprhythm confidence: 0.7442782521247864
deeprhythm bpm: 86.0
==========
Sub Focus -  Vibration (One More Time)
spotify bpm: 174
deeprhythm confidence: 0.738704264163971
deeprhythm bpm: 86.0
==========
Dimension -  DJ Turn It Up
spotify bpm: 174
deeprhythm confidence: 0.9685208201408386
deeprhythm bpm: 86.0
==========
Jack Mirror -  Junipero
spotify bpm: 174
deeprhythm confidence: 0.8193657398223877
deeprhythm bpm: 86.0
==========
Mania -  Reason
spotify bpm: 174
deeprhythm confidence: 0.7582569122314453
deeprhythm bpm: 86.0
==========
Mania -  Time Of Our Lives
spotify bpm: 172
deeprhythm confidence: 0.8535505533218384
deeprhythm bpm: 86.0
==========
Lights Away -  Afterglow
spotify bpm: 172
deeprhythm confidence: 0.6244319677352905
deeprhythm bpm: 86.0
==========
Mania -  Calling Out Your Name
spotify bpm: 87
deeprhythm confidence: 0.5052745938301086
deeprhythm bpm: 86.0
==========
Mandidextrous -  Going Up (feat. Ayah Marar)
spotify bpm: 175
deeprhythm confidence: 0.7808019518852234
deeprhythm bpm: 87.0
==========
Sub Focus -  Off The Ground
spotify bpm: 174
deeprhythm confidence: 0.7823499441146851
deeprhythm bpm: 86.0
==========
Krakota -  Move With Me
spotify bpm: 174
deeprhythm confidence: 0.7999058365821838
deeprhythm bpm: 86.0
==========
1991 -  Worlds Apart
spotify bpm: 174
deeprhythm confidence: 0.926262617111206
deeprhythm bpm: 86.0
==========
Dimension -  Saviour (feat. Sharlene Hector)
spotify bpm: 174
deeprhythm confidence: 0.2915627062320709
deeprhythm bpm: 86.0
==========
Andromedik -  Take Me
spotify bpm: 174
deeprhythm confidence: 0.7987059354782104
deeprhythm bpm: 86.0
==========
Culture Shock -  The Time Is Now
spotify bpm: 174
deeprhythm confidence: 0.7101595997810364
deeprhythm bpm: 86.0
==========
Sub Focus -  Ready To Fly (Sub Focus & Dimension)
spotify bpm: 174
deeprhythm confidence: 0.7157114744186401
deeprhythm bpm: 86.0
==========
Sub Focus -  Trip
spotify bpm: 174
deeprhythm confidence: 0.8367101550102234
deeprhythm bpm: 86.0
==========
Sub Focus -  Don’t You Feel It (Sub Focus & 1991 Remix)
spotify bpm: 174
deeprhythm confidence: 0.9213133454322815
deeprhythm bpm: 86.0
==========
Dimension -  Where Do We Go (feat. Poppy Baskcomb)
spotify bpm: 87
deeprhythm confidence: 0.5965369939804077
deeprhythm bpm: 86.0
==========
Delta Heavy -  Never Alone
spotify bpm: 174
deeprhythm confidence: 0.8914017081260681
deeprhythm bpm: 86.0
==========
Mason -  Perfect (Exceeder) (1991 Remix)
spotify bpm: 174
deeprhythm confidence: 0.7668589353561401
deeprhythm bpm: 86.0
==========
Sub Focus -  Desire (Sub Focus x Dimension)
spotify bpm: 174
deeprhythm confidence: 0.7605651021003723
deeprhythm bpm: 86.0
==========
Supermode -  Tell Me Why (1991 Remix)
spotify bpm: 174
deeprhythm confidence: 0.7539272904396057
deeprhythm bpm: 86.0
==========
Armin van Buuren -  Lose This Feeling (Dimension Remix)
spotify bpm: 174
deeprhythm confidence: 0.6712031960487366
deeprhythm bpm: 86.0
==========
Grafix -  Comedown
spotify bpm: 174
deeprhythm confidence: 0.8425148725509644
deeprhythm bpm: 86.0
==========
Sub Focus -  Alarm
spotify bpm: 174
deeprhythm confidence: 0.8774750828742981
deeprhythm bpm: 86.0
==========
Bou -  Closer (Hedex Remix)
spotify bpm: 175
deeprhythm confidence: 0.6755385994911194
deeprhythm bpm: 87.0
==========
Chase & Status -  BACKBONE
spotify bpm: 88
deeprhythm confidence: 0.542557954788208
deeprhythm bpm: 87.0

[bleugreen]

Interesting findings! If I had to guess, I suspect you've found a genre / drum pattern that was underrepresented in the original training set (only a few thousand public domain songs). I don't have plans to do another run with it any time soon, but if I do I'll try to cover more modern house / edm!

In my testing, I found the model's predictions to be 'questionable' when the confidence level is below ~0.8,

Also, worth noting that Spotify's API is prediction-based, and they include tempo_confidence as well. Would be interesting to see whether their confidence scores are correlated with deeprythm's (which would indicate that the songs have ambiguous tempo)