🎻 Orpheus

Orpheus is a cycle-based live-coding audio environment built as a Rust Cargo workspace.

It provides a pattern-based composition model inspired by TidalCycles and Strudel, a custom DSP engine built on Faust's block diagram algebra, and a ratatui terminal interface that functions as both REPL and session view.

The core premise: music is structure, and structure is best expressed in code. Piano rolls and DAW timelines impose a spatial metaphor on an inherently temporal art. Orpheus treats composition as programming — patterns are expressions, transformations are functions, and a song is a program that produces sound.

For deeper architectural thoughts, see our Design Document.

📦 Workspace Layout

Orpheus is composed of several specialized layers:

• orpheus (Root Binary): The main entry point. Sets up the live audio stream, parses CLI arguments, and launches either the terminal UI or the standard REPL.
• orpheus-pattern: The temporal semantics layer. It implements exact rational time handling ([TimeSpan], [Rational]) and the foundational pattern traits that define how events are scheduled in time.
• orpheus-dsp: The audio rendering and scheduling engine. It turns abstract temporal events into a graph of oscillators, filters, and samples. It runs directly on the audio thread.
• orpheus-lang: The parsing, REPL, and Text User Interface (TUI) layer. It translates the Orpheus language syntax into executable patterns and provides the interactive coding environment.

🚀 Getting Started

Orpheus is built entirely in Rust.

Prerequisites

To build the audio components on Linux, you will need the ALSA development headers:

sudo apt-get install -y libasound2-dev

Building & Running

Run the main application using cargo:

cargo run --release

Orpheus includes a test suite covering the full workspace:

cargo test --workspace --all-targets --all-features

To run the linter and format code:

cargo clippy --workspace --all-targets --all-features -- -D warnings
cargo fmt --all

To read the API documentation:

cargo doc --workspace --open

🧠 Philosophy

• Patterns are first-class: Every musical concept is a pattern that can be queried, composed, and transformed.
• Juxtaposition over ceremony: The most common operation (sequencing) requires the least syntax.
• Explicit composition: Parallel layering, transformation, and structure use explicit keywords.
• Dual-mode typing: Loose inference in the REPL for rapid experimentation, strict inference in .ode files for durable artifacts.