Orchestral Sample Library Articulations Latency Management for Apple Logic Pro
SALT is a suite of MIDI processing scripts built for Apple Logic Pro's Scripter MIDI FX plugin.
It was designed to facilitate MIDI programming and automation by handling the latency inherent in instrument articulations in orchestral sample libraries, managing the attack-dependent timing of each articulation, the true legato transitions, as well as the automatic synchronization of the corresponding Continuous Controllers (CC) and their multi-channel MIDI routing, all within Apple Logic Pro's Scripter MIDI FX plug-in.
Just add a pinch of SALT to your orchestral template. 🧂
Automatically applies specific millisecond delays to MIDI events depending on the currently active articulation.
Different delay values can be used to compensate for articulations with very different attack and transition characteristics, such as:
- Slow Legato transitions
- Sustains and Long articulations
- Slow/Fast Shorts
- Spiccato or Staccato attacks
This allows different articulations to remain rhythmically grid-aligned without relying on a single static Track Delay value.
When MIDI notes are delayed, automation such as Mod Wheel, Expression, Pitch Bend, and other CC data can otherwise arrive too early relative to the delayed notes.
SALT keeps track of the active articulation delay and applies the same timing compensation to incoming CC data, keeping dynamics, expression, and note events synchronized.
Designed to work around some of the limitations of Logic Pro's Articulation Sets when controlling multi-timbral instruments.
CC data received on MIDI Channel 1 can be forwarded across all 16 MIDI channels, allowing automation to reach every articulation or instrument channel while maintaining the appropriate timing compensation.
Full support for Spitfire Audio's UACC via Velocity articulation switching.
A single trigger note can be used while its Velocity value determines the selected articulation and corresponding delay.
CC Sync Edition
File: SALT V5.3 - KS Command Center (CC Sync).js
The core engine for standard Keyswitch (KS) libraries.
It allows you to define MIDI pitch ranges for:
- Legatos
- Longs
- Shorts
Each group can be assigned a specific millisecond delay.
Incoming CC data is automatically synchronized with the delay of the currently active articulation.
CC Sync & CH Forward
File: SALT V6.4 - KS Command Center Hybrid (CC Sync & CH Forward).js
Built for more complex multi-timbral routing.
This version introduces a Hybrid Radar, allowing articulations to be triggered either by:
- Standard Keyswitches
- Specific isolated MIDI Channels
It also includes the Multi-Channel Forwarding Engine.
Any CC data received/recorded on Channel 1 is automatically cloned across Channels 2–16 while retaining the appropriate articulation delay.
UACC Velocity & CC Sync
File: SALT V7 - Spitfire (UACC Velocity & CC Sync).js
Designed specifically for Spitfire Audio libraries using UACC via Velocity.
Instead of mapping articulation switches across multiple notes, the script monitors a single Trigger Note — for example, C-2.
The Velocity value of that trigger note determines:
- The active articulation mode
- The corresponding MIDI delay
CC data is then synchronized with the currently active delay.
- Open Logic Pro and insert the Scripter MIDI FX plugin on your instrument track.
- Click
Open Script in Editor. - Copy the contents of the desired
.jsfile from this repository and paste it into the Scripter Editor, replacing the default example code. - Click
Run Script. - Close the editor.
You can now configure your specific:
- Delay timings
- Keyswitch ranges
- MIDI channels
- UACC trigger notes
- Articulation mappings
directly from the Scripter Plugin UI parameters.
Tip: You can save the script using the Save As... drop-down menu option in the Scripter UI so you do not need to paste the code again every time you use it.
SALT was developed to act as an invisible "First Officer" between MIDI input, articulation management, and orchestral sample-engine rendering.
The goal is simple: reduce the manual timing and routing work required when building, programming, and performing with large orchestral templates.
Feel free to fork, modify, adapt, and integrate the scripts into your own orchestral workflows and templates.
- Apple Logic Pro
- Scripter MIDI FX Plugin
- JavaScript syntax and API as supported by Logic Pro Scripter
Important: Logic Pro's Scripter environment uses its own JavaScript API and execution model. These scripts are intended specifically for Logic Pro Scripter and should not be treated as conventional browser or Node.js JavaScript.