Calliope is a browser-based tool for co-creative multi-track music composition, developed by the Metacreation Lab. It supports multiple generative tasks, including bar-level in-filling, complete multi-track generation, rhythm and melody creation, harmonization, and chord progression generation. It enables both amateur and professional composers to create, edit, and generate MIDI directly in the browser, letting them experiment and explore new possibilities in musical phrasing.
Calliope provides a flexible interface for advanced MIDI manipulation. Users can visualize tracks, apply generative edits, and export outputs as MIDI files or stream them in real time to a digital audio workstation (DAW).
Composers can adjust parameters at both global (e.g., temperature) and track-specific levels (e.g., note density, polyphony range, note duration). They can add or remove tracks, limit generation to selected subsets, and use batch generation (5–1000 excerpts per request). Results can then be refined through an interactive loop of generation and playback, creating a dynamic, hands-on compositional experience. Calliope has been showcased at the AI Song Contest 2022, where generated works can be heard here. https://www.metacreation.net/projects/aisongcontest-2022
Built on Apollo—an interactive platform for corpus-based music algorithms—and integrating the Transformer-based Multi-Track Music Machine (MMM). The system is implemented with Node.js, HTML, CSS, and JavaScript, using MongoDB and connecting to MMM via a Python runtime. MMM’s native Python interface handles batch generation, with processing times ranging from 3 seconds to 10 minutes depending on note density, enabling both scalable and interactive composition workflows.
