For AL version: 2.1.0 and above
This script has an associated skin - see here.
Download a package containing the script, the skin, some brief instructions, an example Ableton Live set and a FCB1010 preset here.
A longer tutorial is available on Axel's blog.
The script works with four instances of Augustus Loop 2.1
Select loop number 1 by sending Midi CC12 value 1.
Send Midi NoteOn 1, record something into the first loop, send NoteOn 1 again to close the loop. You've created the master loop.
Add more layers to the loop by sending NoteOn 1 or select another plugin instance by sending Midi CC12 value 2 - 4.
Change the lengths of the selected loop with Midi NoteOn/Off 4 and 5. If there is more than one second between the NoteOn and the NoteOff the beat number doubles/halves, else one beat is added/subtracted.
Toggle the filter and freeze functions by sending Midi NoteOn/Off 2. If there is more than one second between the NoteOn and the NoteOff the filter is engaged, else the loop is frozen.
Toggle mute and reverse functions by sending Midi NoteOn/Off 3. If there is more than one second between the NoteOn and the NoteOff the loop is reversed, else its output level is set to 0.
Control the Feedback and Pitch value of the selected loop with Midi CC4 and CC6. Or control the global feedback and Volume with Midi CC13 and CC14 when all loops are selected.
Reset one or all instances by sending Midi NoteOn 1 (velocity 100) and waiting for 1.5 seconds before sending NoteOff 1 (velocity 0).
midi.lua contains comments that might also be useful.
The GUI is not needed in order for the midi.lua to work. It has a much smaller footprint though as the default GUI so it's easy to fit all four instances of the plugin on one screen. If you want to use it, copy it to Augustus Loops skin folder. The very smallish grey thingy at on left of the GUI is the preferences button.