# AccoMontage2: A Complete Harmonization and Accompaniment Arrangement System

arXiv: https://arxiv.org/abs/2209.00353 · HTML: https://mlsanity.com/paper/2209.00353/

## Key facts

- Cited by 8 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 1 Sep 2022.

## Built on by (most cited first, 8 of 8)

- [Loop Copilot: Conducting AI Ensembles for Music Generation and Iterative Editing](https://mlsanity.com/paper/2310.12404/) (2023)
- [Structured Multi-Track Accompaniment Arrangement via Style Prior Modelling](https://mlsanity.com/paper/2310.16334/) (2023)
- [Learning Interpretable Low-dimensional Representation via Physical Symmetry](https://mlsanity.com/paper/2302.10890/) (2023)
- [Unifying Symbolic Music Arrangement: Track-Aware Reconstruction and Structured Tokenization](https://mlsanity.com/paper/2408.15176/) (2024)
- [SymphonyGen: 3D Hierarchical Orchestral Generation with Controllable Harmony Skeleton](https://mlsanity.com/paper/2604.25498/) (2026)
- [AI Harmonizer: Expanding Vocal Expression with a Generative Neurosymbolic Music AI System](https://mlsanity.com/paper/2506.18143/) (2025)
- [Unsupervised Lead Sheet Generation via Semantic Compression](https://mlsanity.com/paper/2310.10772/) (2023)
- [Structure-Aware Piano Accompaniment via Style Planning and Dataset-Aligned Pattern Retrieval](https://mlsanity.com/paper/2602.15074/) (2026)

## Abstract (arXiv)

We propose AccoMontage2, a system capable of doing full-length song harmonization and accompaniment arrangement based on a lead melody. Following AccoMontage, this study focuses on generating piano arrangements for popular/folk songs and it carries on the generalized template-based retrieval method. The novelties of this study are twofold. First, we invent a harmonization module (which AccoMontage does not have). This module generates structured and coherent full-length chord progression by optimizing and balancing three loss terms: a micro-level loss for note-wise dissonance, a meso-level loss for phrase-template matching, and a macro-level loss for full piece coherency. Second, we develop a graphical user interface which allows users to select different styles of chord progression and piano texture. Currently, chord progression styles include Pop, R&B, and Dark, while piano texture styles include several levels of voicing density and rhythmic complexity. Experimental results show that both our harmonization and arrangement results significantly outperform the baselines. Lastly, we release AccoMontage2 as an online application as well as the organized chord progression templates as a public dataset.