Tipiano: Cascaded Piano Hand Motion Synthesis via Fingertip Priors
Authors: Joonhyung Bae, Kirak Kim, Hyeyoon Cho, Sein Lee, Yoon-Seok Choi, Hyeon Hur, Gyubin Lee, Akira Maezawa, Satoshi Obata, Jonghwa Park, Jaebum Park, Juhan Nam
Organizations: Korea Advanced Institute of Science and Technology (KAIST), South Korea · Seoul National University, South Korea · YAMAHA, Japan
Synthesizing realistic piano hand motions requires both precision and naturalness. Physics-based methods achieve precision but produce stiff motions; data-driven models learn natural dynamics but struggle with positional accuracy. Piano motion exhibits a natural hierarchy: fingertip positions are nearly deterministic given piano geometry and fingering, while wrist and intermediate joints offer stylistic freedom. We present [OURS], a four-stage framework exploiting this hierarchy: (1) statistics-based fingertip positioning, (2) FiLM-conditioned trajectory refinement, (3) wrist estimation, and (4) STGCN-based pose synthesis. We contribute expert-annotated fingerings for the FürElise dataset (153 pieces, ~10 hours). Experiments demonstrate F1 = 0.910, substantially outperforming diffusion baselines (F1 = 0.121), with user study (N=41) confirming quality approaching motion capture. Expert evaluation by professional pianists (N=5) identified anticipatory motion as the key remaining gap, providing concrete directions for future improvement.
Figures & tables
Figure 1. Overview of Tipiano. Our four-stage cascade exploits decreasing ambiguity from fingertips to intermediate joints.
Dataset
Pieces
Notes
Hours
Performer
Annotation
Boundary
PIG a
150
100K
—
Expert
Expert
✗
ThumbSet b
2.5K
—
—
—
Amateur
✗
PianoVAM c
106
1.05M
21
Amateur
Researcher
✗
Tipiano
153
340K
10
Expert
Expert
✓
Table 1. Piano fingering datasets comparison. Fingering provides per-note finger-key contact assignments, enabling position prior construction.
Figure 2. The Tipiano pipeline. From MIDI and fingering, four cascaded stages synthesize hand motion: (1) statistics-based fingertip positioning, (2) FiLM-conditioned trajectory refinement with geometric constraints, (3) wrist estimation via offset priors, and (4) STGCN-based full pose synthesis.
Method
Task Accuracy
Position (mm) ↓
Accel. Ratio ∗
Prec. ↑
Rec. ↑
F1 ↑
Fingertip
Wrist
Full
Fingertip
Wrist
Full
Left
Right
Both
Left
Right
Both
Left
Right
Both
Left
Right
Both
Left
Right
Both
Left
Right
Both
FürElise Dataset
.839
.670
.739
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
S2C a
.100
.163
.121
74.1
64.3
69.2
65.4
58.5
61.9
69.6
59.9
64.8
0.74
0.67
0.70
0.75
0.79
0.77
0.77
0.72
0.75
RoboPianist b
.996 †
.783 †
.877 †
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Tipiano (Stage 1)
.798
.991
.882
50.0
49.7
49.8
—
—
—
—
—
—
3.06
3.45
3.79
—
—
—
—
—
—
Table 2. Quantitative comparison. ↓ : lower is better, ↑ : higher is better. Accel. Ratio ∗ : ratio of predicted to GT acceleration magnitude; ≈1.0 matches GT dynamics, <1.0 lower acceleration, >1.0 higher acceleration. F1 scores are evaluated on Stage 2.2 output (post-refinement, pre-smoothing) across all stages to ensure consistent key contact measurement; smoothing improves motion quality but slightly shifts press timing. Position and Accel. metrics reflect each stage’s actual output.
Figure 3. User study results ( N=41 ). (a) Preference for Tipiano over baselines. (b) Mean preference gap from FürElise dataset on 7-point Likert scale (lower is better; 0 = no preference). Tipiano achieves the smallest gap across all dimensions. Error bars: 95% CI. All p<.001 .
Configuration
Prec ↑
Recall ↑
F1 ↑
Δ F1
Full (proposed)
0.847
0.988
0.912
—
w/o Y-axis masking
0.846
0.909
0.876
− 0.036
Raw MIDI features
0.829
0.986
0.901
− 0.011
Concat (no FiLM)
0.838
0.987
0.907
− 0.005
Table 3. Design choice ablation on the test set. All variants are compared at the Stage 2.2 output.
Audio-driven bimanual piano motion generation requires precise modeling of complex musical structures and dynamic cross-hand coordination. However, existing methods often rely on acoustic-only representations lacking symbolic priors, employ inflexible interaction mechanisms, and are limited to computationally expensive short-sequence generation. To address these limitations, we propose PianoFlow, a flow-matching framework for precise and coordinated bimanual piano motion synthesis. Our approach strategically leverages MIDI as a privileged modality during training, distilling these structured musical priors to achieve deep semantic understanding while maintaining audio-only inference. Furthermore, we introduce an asymmetric role-gated interaction module to explicitly capture dynamic cross-hand coordination through role-aware attention and temporal gating. To enable real-time streaming generation for arbitrarily long sequences, we design an autoregressive flow continuation scheme that ensures seamless cross-chunk temporal coherence. Extensive experiments on the PianoMotion10M dataset demonstrate that PianoFlow achieves superior quantitative and qualitative performance, while accelerating inference by over 9\times compared to previous methods.
Xuan Wang, Kai Ruan, Jiayi Han +2
Zhejiang University Hangzhou, Zhejiang, China · Renmin University of China Beijing, China · Beijing Forestry University Beijing, China +1
Machine learning tools have significantly aided automatic piano music transcription; however, this domain has focused primarily on accurately predicting the pitches and timings of played notes. To produce sheet music for the piano, notes must be separated into two staves, one for each hand, and good sheet music often contains fingering annotations to guide the player when sight-reading or learning fast or complex pieces. We propose 8 statistical approaches for combined hand and fingering annotation of transcribed piano notes, including baseline hidden Markov models, rule-based methods, a synthesis of existing approaches, and N-gram language models. Furthermore, we develop a pipeline for complete transcription from piano audio to fingering-annotated sheet music. Evaluations with the PIG dataset demonstrate that our Synthesis model achieves a hand separation accuracy of 90.8% and a joint hand and finger annotation accuracy of 56.6%. These approaches serve as a new baseline for further research into this problem, while our pipeline demonstrates the feasibility of a combined system for automated note transcription, hand separation, and fingering annotation.
Daniel Penner, Abram Hindle
Department of Computing Science, University of Alberta, Edmonton, Alberta, Canada
Music information retrieval research on piano performance increasingly involves diverse modalities of data and annotations beyond audio and MIDI. We present SKY-Piano, a multimodal piano performance dataset that includes 11 hours of performance recordings of motion, multi-view video, audio, MIDI from 7 professional and 12 amateur pianists along with MusicXML scores. The performance pieces were selected considering playing technique, difficulty, and performer expertise on a shared core repertoire. The motion data include both hand and body motion, released in both flagged form, where samples lost to marker occlusion are marked as unreliable, and imputed form, where those gaps are reconstructed, together with Visual3D body-segment kinematics and other time-synchronized modalities. To easily browse different modalities of data at a glance, we provide an interactive web browser. In addition, we developed a fingering annotation model and tool for deriving pseudo fingering annotations from the MIDI and motion data. Lastly, we present MIDI-to-motion generation through a fine-tuning experiment as a use case of the dataset.
Joonhyung Bae, Dawon Park, Taegyun Kwon +10
KAIST · Seoul National University · Yamaha Corporation