Alternator: A General-Purpose Generative Music Player

Computers are a powerful technology for music playback: as general-purpose computing machines with capabilities beyond the fixed-recording playback devices of the past, they can play generative music with multiple outcomes, or computational compositions that are not fully determined until they are played. However, there is no convenient platform for distributing generative music in a way that captures the space of all possible outputs. This absence hinders composers’ and listeners’ access to the possibilities of computational playback.
In this paper, we address the problem of distributing generative music. We present a) a format for bundling computational compositions with static assets in self-contained packages and b) a music player for finding, fetching, and playing/executing these compositions. These tools are built for generality to support a variety of approaches to making music with code and remain language-agnostic. We take advantage of WebAssembly and related tools to enable the use of general-purpose languages such as C, Rust, JavaScript, and Python and audio languages such as Pure Data, RTcmix, Csound, and ChucK.We use AudioWorklets and Web Workers to enable scalable distribution via clientside playback. And we present the user with a music player interface that aims to be familiar while also presenting the possibilities of generative music.