Machine learning has made strong progress on music tasks, both as assistive tools and as creative partners. However, most systems train on multitrack corpora that emphasize pop and rock. Jazz, with improvisation at the core of its practice, still lacks a well-annotated corpus of clean per-stem combo recordings on standards. We introduce JazzSAMBA (Jazz Synchronous and Asynchronous Multi-take Band Audio) to fill this gap: the first originally recorded jazz-combo multitrack dataset of standards with asynchronous (overdubbed) and synchronous (live ensemble) protocols, preferred and alternate takes chosen by the musicians, and timed annotations for bars, chords, sections, and soloists. JazzSAMBA covers 76 standards by eight musicians on drums, bass, piano, trumpet, and saxophone, with per-stem audio, mixtures, and MIDI. It can support chart-conditioned accompaniment, combo source separation, and form-aware music information retrieval. We demonstrate the dataset on two tasks: a jazz combo source-separation baseline and a chart-conditioned accompaniment ablation. The dataset, code, and samples are linked from the project demo page.
Figures & tables
Figure 1: JazzSAMBA overview ( 50 asynchronous / 26 synchronous songs; about 8.1 h preferred-take, about 16.1 h both tiers). Labels 1 and 2 are take tiers. Asynchronous takes overdub in sequence (drums first; dotted arrows); synchronous takes record the whole ensemble together (dashed lines). Preferred mixtures are annotated for bars, chords, sections, and soloists; alternate async annotations are copied, while sync takes are labeled separately.
Corpus
Stems
Takes
Dual
Chords
Sections
Soloists
MIDI
MUSDB18 [ 19 ]
✓
MoisesDB [ 17 ]
✓
Slakh2100 [ 15 ]
✓
✓
Jazz Trio Database [ 5 ]
✓ †
✓ ∗
Jazz Harmony [ 7 ]
✓
✓
Weimar Jazz Database [ 18 ]
✓
✓
✓
✓ ∗
Table 1: JazzSAMBA vs. selected related corpora.
Protocol
Stems
Annotations
GT MIDI
Clean
Bleed
Timed
Shared
Drums
Piano
Asynchronous
✓
✓
✓
✓
✓
Synchronous
✓
✓
✓
Table 2: Asynchronous vs. synchronous protocol contents. Shared marks preferred labels copied to the alternate tier. GT denotes ground-truth; remaining MIDI is from MuScriptor AMT [ 20 ] . For stems with bleed, we also ship a Wiener-style de-bleeded version [ 10 ] . All audio is 48 kHz.
Model
FT
Drums
Bass
Piano
Horns
HT-Demucs 6s
—
13.01
15.07
4.92
—
JazzSAMBA
15.09
17.03
9.42
14.62
ChoraleBricks
—
15.02
—
8.98
Open-Unmix
—
5.24
5.63
—
—
JazzSAMBA
8.37
9.74
6.07
9.38
ChoraleBricks
—
5.63
—
− 0.66
Table 3: Asynchronous-test SI-SDR ↑ (dB), full-track ( n=5 ). Dashes mark unfair zero-shot or ChoraleBricks cells (no matching stem supervision). We bold the best reportable score within each model.
COCOLA ↑
Beat F1 ↑
Protocol
Condition
D
B
P
H
D
B
P
H
Asynchronous
Ground Truth
55.6
62.1
63.4
64.5
1.00
0.80
0.48
0.29
Listen-Only
52.2
60.4
59.8
61.4
0.23
0.16
0.13
0.02
+ Sections
50.7
59.8
59.7
61.9
0.29
0.09
0.13
0.05
+ Chords
52.5
60.6
60.0
62.3
0.30
0.09
0.15
0.06
+ Both
51.4
60.4
59.9
61.7
0.34
0.10
0.12
0.04
Table 4: Accompaniment scores on 60 s free-run from form landmarks (asynchronous test n=5 , synchronous test n=3 ; mean over landmarks). D, B, P, and H denote drums, bass, piano, and horns. Ground Truth scores the annotated target stem against the condition mix. We bold the best score per column among chart conditions (excluding Ground Truth).