Structured Multi-Track Accompaniment Arrangement via Style Prior Modelling

TL;DR

This paper introduces a novel multi-stage music arrangement system that uses style prior modeling and a multi-stream Transformer to generate structured, coherent, and controllable multi-track accompaniments from lead sheets, improving quality and efficiency.

Contribution

The proposed method uniquely combines style prior modeling with vector quantization and a multi-stream Transformer for flexible, structured music arrangement from lead sheets.

Findings

Enhanced coherence and structure in generated arrangements

Supports multiple music genres with controllable style features

Outperforms existing baselines in arrangement quality

Abstract

In the realm of music AI, arranging rich and structured multi-track accompaniments from a simple lead sheet presents significant challenges. Such challenges include maintaining track cohesion, ensuring long-term coherence, and optimizing computational efficiency. In this paper, we introduce a novel system that leverages prior modelling over disentangled style factors to address these challenges. Our method presents a two-stage process: initially, a piano arrangement is derived from the lead sheet by retrieving piano texture styles; subsequently, a multi-track orchestration is generated by infusing orchestral function styles into the piano arrangement. Our key design is the use of vector quantization and a unique multi-stream Transformer to model the long-term flow of the orchestration style, which enables flexible, controllable, and structured music generation. Experiments show that by factorizing the arrangement task into interpretable sub-stages, our approach enhances generative capacity while improving efficiency. Additionally, our system supports a variety of music genres and provides style control at different composition hierarchies. We further show that our system achieves superior coherence, structure, and overall arrangement quality compared to existing baselines.