Abstract:Reactive dance generation (RDG) produces follower movements conditioned on guiding dancer and music while ensuring spatial coordination and temporal coherence. However, existing methods overemphasize global constraints and optimization, overlooking local information, such as fine-grained spatial interactions and localized temporal context. Therefore, we present ReactDance, a novel diffusion-based framework for high-fidelity RDG with long-term coherence and multi-scale controllability. Unlike existing methods that struggle with interaction fidelity, synchronization, and temporal consistency in duet synthesis, our approach introduces two key innovations: 1)Group Residual Finite Scalar Quantization (GRFSQ), a multi-scale disentangled motion representation that captures interaction semantics from coarse body rhythms to fine-grained joint dynamics, and 2)Blockwise Local Context (BLC), a sampling strategy eliminating error accumulation in long sequence generation via local block causal masking and periodic positional encoding. Built on the decoupled multi-scale GRFSQ representation, we implement a diffusion model withLayer-Decoupled Classifier-free Guidance (LDCFG), allowing granular control over motion semantics across scales. Extensive experiments on standard benchmarks demonstrate that ReactDance surpasses existing methods, achieving state-of-the-art performance.