Terrarum Locus
MIDI Generator
Locus app icon

Locus

An AUv3 MIDI generator for iOS — a locked-loop mutator that creates evolving one-bar loops without losing their identity. Freeze a loop to build on it, or raise the variation and let it mutate while preserving its character.

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See Locus in Action

Quick Start

  1. Open your Audio Unit host (AUM, Drambo, Logic Pro).
  2. Add Locus as an AUv3 MIDI effect or MIDI generator.
  3. Route Locus MIDI output to a synth on another track.
  4. Choose an archetype and press Create.
  5. Adjust Variation to freeze or evolve the loop.
Note: Locus outputs MIDI only. It will not make sound until routed to a synth.

What Makes Locus Different

Frozen loops
Variation at 0 never changes — a stable foundation to build tracks on
Evolving loops
Variation above 0 mutates the loop gradually while preserving its identity
Deterministic
Same settings always produce the same output
RT-safe
Real-time-safe audio thread — zero glitches under load

The 13 Archetypes

Each archetype gives Locus a distinct musical personality to start from.

  • Puncture — sharp, accented pointillism
  • Groove — swung, feel-forward motion
  • Pulse — steady, driving repetition
  • Cascade — rolling, descending runs
  • Thump — weighty, low-centered hits
  • Cluster — dense, compact groupings
  • Chaos — unpredictable, scattered energy
  • Even Pulse — grid-aligned even spacing
  • Interlock — two-part hocketing patterns
  • Call/Answer — conversational phrasing
  • Arc — rising and falling shapes
  • Wander — meandering, free motion
  • Sparse Fractal — self-similar space

Usage Notes

Plugin type
MIDI only (no audio output)
Best hosts
AUM, Drambo, Logic Pro, GarageBand
Grid
One-bar motifs on a fixed 16-step grid
Transport
Syncs to the host clock at bar boundaries

Common Questions

  • No sound: Locus outputs MIDI only. Route it to a synth track.
  • The loop keeps changing: Lower the Variation. At 0 the loop is frozen and never changes.
  • It sounds different each time I load it: Same settings always produce the same output. Check that the archetype, seed, and variation match.
  • Changes feel delayed: Locus applies changes at bar boundaries for clean, glitch-free timing.