Locus
Generative MIDI sequencer
$4.99 · Designed for iPad. Not verified for macOS.
Special introductory sale! Generate endless melodic ideas from 13 archetypes. Seed-derived motifs and real-time evolution. Standalone and AUv3 plugin support.
Locus is a generative MIDI sequencer that creates evolving melodic motifs and sends them to your favorite synths. Designed for techno, ambient, IDM, and experimental electronic music, it turns a single seed into fresh musical ideas across thirteen generative archetypes, from acid-style grooves and cascading arpeggios to sparse fractals and interlocking pulses.
Use Locus as a standalone app or as an AUv3 MIDI effect inside hosts like AUM, Logic, Cubasis, and Drambo. Every generated pattern plays in sync with your host and routes over MIDI to any instrument you choose.
GENERATION
Press CREATE and Locus composes a new motif from the current archetype, rooted in your chosen key and scale. Each archetype has its own rhythmic and melodic character: Groove, Cascade, Arc, Wander, Call & Answer, Chaos, Pulse, Even Pulse, Sparse Fractal, Interlock, Cluster, Puncture, and Thump. Generation is seed-derived, so the same settings always reproduce the same pattern.
EVOLVE
Push EVOLVE to generate controlled variations of the current motif. Keep what works, mutate what doesn't. Rhythm and pitch shift in musically coherent ways without losing the pattern's identity.
FEEL
Shape the musical foundation with Root, Scale, Timing, Steps, Octave range, Swing, Dynamics, and Density. 25 scales keep everything in key. Raise density to fill the grid or thin it out for space.
EDIT & SLIDE
Engage Pattern Lock to edit the authored pattern directly: rotate, move, and transpose notes, or undo and redo. The SLIDE knob adds per-note slides with 303-style legato, gliding between pitches for classic acid phrasing. Slides even carry across density-thinned notes.
SCENES
Capture complete musical setups in sixteen scene slots and chain them into full arrangements. Each scene remembers its pattern, archetype, feel settings, and slide amount.
STANDALONE & AUV3
Use Locus as a standalone app or as an AUv3 MIDI effect. It runs in AUv3 hosts such as AUM, Logic, Cubasis, and Drambo, following host transport and clock.
KEY FEATURES
• Generative MIDI sequencer for melodic ideas
• 13 archetypes: Groove, Cascade, Arc, Wander, Call & Answer, Chaos, Pulse, Even Pulse, Sparse Fractal, Interlock, Cluster, Puncture, Thump
• Seed-derived generation, reproducible from your settings
• Evolve, Feel, and Edit scopes for total musical control
• Per-note slides with 303-style legato
• 25 scales with snap-to-scale pitch
• Swing, dynamics, and density shaping
• Pattern Lock with rotate, move, transpose, undo/redo
• 16 scenes with chain editor for full arrangements
• AUv3 MIDI effect + standalone app
• Host sync and MIDI routing to any instrument
MANUAL & TUTORIALS
• See the "Help" page in the app for the full manual and tutorials
• Alternatively, visit https://terrarum.net/locus.html to read them online
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Joe Topjian, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Joe Topjian
- Size
- 12.9 MB
- Category
- Music
- Compatibility
Requires iOS 17.6 or later.
- iPhone
Requires iOS 17.6 or later. - iPad
Requires iPadOS 17.6 or later. - Mac
Requires macOS 14.6 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.3 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Joe Topjian
