In this paper we address the design and implementation of custom controller interfaces, bridging the issue of user mapping between action and sound in interactive music systems. A simple framework utilizing functional specifications for musical interfaces and their mappings is presented, in terms of a subset of Scalable Vector Graphics (SVG); interfaces can be described using a simple Haskell based `controller DSL' or equally using a vector drawing application (i.e. Illustrator).
We demonstrate the practical use of our system for specifying interfaces as SVGs combined with Faust, a functional DSL for Digital Signal Processing (DSP), in the context of building digital musical instruments. We combine these into a hardware and software audio toolkit, with synthesizers, a sampler, effects, and sequencers. Written in the systems programming language Rust, it demonstrates utilizing the output of our DSLs, providing a type safe and high-level framework for DSP and interface development, with the performance benefits of Rust. Working examples
of custom interfaces are described, using ROLI's Lightpad and Sensel's Morph.