Aevum is a macOS instrument for live AI music performance. Import songs, auto-extract beat-aligned loops, and morph between them in real time — every generation parameter under your MIDI controller.
aevum, lat. — an age; a long, indefinite span of time
Every control is live, every parameter is MIDI-learnable, and the model runs at 25 Hz so morphing happens with no audio dropouts.
Drag in any WAV/MP3/FLAC. Aevum beat-tracks it, slices 2/4-bar candidates at downbeat boundaries, embeds each with MusicCoCa, and ranks them by energy.
Six blend slots map onto a 2D prompt surface. Drag the cursor — inverse-distance weighting re-blends the MusicCoCa tokens every 40 ms, continuously.
Notes steer pitch live. CC maps to every MRT2 parameter — CFG, temperature, top-k, masking, drumless, onset mode — and the map is MIDI-learnable.
Prefill the transformer with a clip's audio — SpectroStream encode → KV cache — and generation continues from where the loop ends, matching its style.
Cosine similarity over 768-dim MusicCoCa embeddings. Three modes: smooth walk, max-contrast drama, or hierarchical clusters — auto-advance optional.
Capture slot arrangements + pad positions as named scenes. Focus mode enlarges the prompt surface for the live set — sidebar and params fold away.
Drop in audio files. Aevum decodes, beat-tracks, slices, and embeds each loop automatically.
Double-click clips to load them into the six blend slots. Drag slot dots to lay out the morph space.
Move the cursor on the 2D pad. The model crossfades between styles continuously — no resets.
Drive it from a MIDI controller, capture scenes, record the set to ~/Music/Aevum as a WAV.
The app is ~130 MB. On first launch it pulls the model weights from HuggingFace (~1.8 GB, one time).
Aevum-*.dmg from GitHub Releases.xattr -cr /Applications/Aevum.appxattr command once — macOS remembers the app after that.xattr? Aevum ships unsigned (no $99/yr Apple Developer account) to keep it free. macOS quarantines unsigned downloads and on recent versions refuses to launch them with a misleading "damaged" message — xattr -cr clears that flag so Gatekeeper lets it run. If you haven't dragged Aevum to Applications yet, run xattr -d com.apple.quarantine ~/Downloads/Aevum-*.dmg on the DMG first. If you already ran mrt models download, Aevum reuses those files — no re-download.
mrt2_smallM2 Max / M3 Pro / M4 Pro+ for mrt2_base.Yes, in the sense that audio is generated by Magenta RealTime 2 — a 230M-parameter transformer on Apple's MLX runtime. But you're not pressing a button and waiting: you drive it live. Think of Aevum as the instrument and the model as the oscillator.
No. Only the first launch downloads the model (~1.8 GB from HuggingFace). After that, Aevum is fully offline — the model runs on your Mac's GPU via MLX.
Yes — that's the whole point. Drag in any WAV/MP3/FLAC/M4A. Aevum beat-tracks, slices loops at downbeat boundaries, and embeds them so you can morph between your own material live. Use material you have the rights to perform.
The app is free and open source under the MIT license. The bundled Magenta RealTime 2 submodule is Apache-2.0 and the model weights are released by Google under CC-BY-4.0 (see HuggingFace).
Google's real-time music generation model — 230M params (mrt2_small) or 2.4B (mrt2_base). Aevum is an independent native macOS front-end for it; it isn't affiliated with Google. More at magenta.withgoogle.com.
Not currently. MLX (the inference runtime) is Apple Silicon only, and the UI is native SwiftUI. There's no Electron, no cross-platform layer — that's the point.
Yes. Hit the record button in the transport bar — Aevum captures the live stereo output to ~/Music/Aevum/ as a 48 kHz WAV. Import that into your DAW or upload straight to SoundCloud/Bandcamp.
That's Gatekeeper, not a real corruption. Browsers tag unsigned downloads with a quarantine flag, and recent macOS versions refuse to launch quarantined unsigned apps with a misleading "damaged" message instead of the friendlier "unidentified developer" one. Clear the flag in Terminal:xattr -cr /Applications/Aevum.app
If the DMG itself is flagged before you can mount it, run xattr -d com.apple.quarantine ~/Downloads/Aevum-*.dmg first, then mount + drag. You only do this once. The real long-term fix is notarization, which requires a paid Apple Developer account — not in scope for v0.1.
The model weights are ~1.8 GB. Bundling them in the app would make the download painful for everyone, even people who already have the files. The first-run downloader checks for existing files at ~/.cache/magenta-rt-v2 and skips them.