Large Language Models: From Notes to Musical Form

While many topics of the learning-based approach to automated music generation are under active research, musical form is under-researched. In particular, recent methods based on deep learning models generate music that, at the largest time scale, lacks any structure. In practice, music longer than one minute generated by such models is either unpleasantly repetitive or directionless. Adapting a recent music generation model, this paper proposes a novel method to generate music with form. The experimental results show that the proposed method can generate 2.5-minute-long music that is considered as pleasant as the music used to train the model. The paper first reviews a recent music generation method based on language models (transformer architecture). We discuss why learning musical form by such models is infeasible. Then we discuss our proposed method and the experiments.

Musical Form Generation

While recent generative models can produce engaging music, their utility is limited. The variation in the music is often left to chance, resulting in compositions that lack structure. Pieces extending beyond a minute can become incoherent or repetitive. This paper introduces an approach for generating structured, arbitrarily long musical pieces. Central to this approach is the creation of musical segments using a conditional generative model, with transitions between these segments. The generation of prompts that determine the high-level composition is distinct from the creation of finer, lower-level details. A large language model is then used to suggest the musical form.

Generating symbolic music using diffusion models

Probabilistic Denoising Diffusion models have emerged as simple yet very powerful generative models. Diffusion models unlike other generative models do not suffer from mode collapse nor require a discriminator to generate high quality samples. In this paper, we propose a diffusion model that uses a binomial prior distribution to generate piano-rolls. The paper also proposes an efficient method to train the model and generate samples. The generated music has coherence at time scales up to the length of the training piano-roll segments. We show how such a model is conditioned on the input and can be used to harmonize a given melody, complete an incomplete piano-roll or generate a variation of a given piece. The code is shared publicly to encourage the use and development of the method by the community.