AI Harmonizer: Expanding Vocal Expression with a Generative Neurosymbolic Music AI System

TL;DR

AI Harmonizer is a novel system that autonomously generates rich four-part vocal harmonies using generative AI, enhancing solo vocal melodies without requiring prior harmonic input, thus advancing AI-assisted musical performance.

Contribution

The paper introduces a new AI system that automatically creates coherent vocal harmonies from melodies without user-specified harmonic input, integrating advanced AI techniques with symbolic music models.

Findings

Successfully generates four-part harmonies from melodies

Operates offline with potential for real-time adaptation

Provides a new tool for vocal performance and composition

Abstract

Vocals harmonizers are powerful tools to help solo vocalists enrich their melodies with harmonically supportive voices. These tools exist in various forms, from commercially available pedals and software to custom-built systems, each employing different methods to generate harmonies. Traditional harmonizers often require users to manually specify a key or tonal center, while others allow pitch selection via an external keyboard-both approaches demanding some degree of musical expertise. The AI Harmonizer introduces a novel approach by autonomously generating musically coherent four-part harmonies without requiring prior harmonic input from the user. By integrating state-of-the-art generative AI techniques for pitch detection and voice modeling with custom-trained symbolic music models, our system arranges any vocal melody into rich choral textures. In this paper, we present our methods, explore potential applications in performance and composition, and discuss future directions for real-time implementations. While our system currently operates offline, we believe it represents a significant step toward AI-assisted vocal performance and expressive musical augmentation. We release our implementation on GitHub.