The basics of Step Sequencer are in the Logic Pro course. Logic 12 rebuilt a lot of it, and the parts that got rebuilt are the parts that make a pattern sound played rather than programmed.
Edit modes are the whole point
Every row can be edited in a different mode, and each mode writes a different value per step. The ones worth your time:
- Note Repeat - drag vertically in a step for 1 to 16 repeats. Rolls, stutters, trap hats, done in one gesture.
- Chance - the probability that step fires at all. The single best cure for a loop that gets boring after eight bars.
- Step Rate - per-step timing, so one part of the bar can run at a different division from the rest.
- Skip - take a step out of the cycle entirely, which shifts everything after it and shortens the pattern's feel without changing its length.
- Loop and Offset - repeat and nudge sections of a row against the others.
Chord degree rows
A note row no longer has to be a fixed pitch. Add a row as Chord Degrees and it follows the Chord track or the region chords instead - so the sequence transposes itself through the progression rather than sitting on one chord while the song moves underneath it.
Randomize properly
The Randomize button rolls the current edit mode. Which is more useful than it sounds, because it randomises that mode only - randomise the velocities without touching which steps are on.
- Button - randomise the active edit mode across the whole pattern.
- Row button - same, for one row.
- Control-click the button - the Randomize dialog, where you set Probability and pick the mode: probability, offset, or range.
On a pattern with both note and automation rows you can randomise velocity and value separately, and limit it to note rows only or automation rows only.
Playback modes
Set per pattern or per row: forward, reverse, and the less obvious ones that walk the row in other orders. Per-row is where this earns its keep - put the hats on forward and the percussion on a different mode and the loop stops repeating identically.
Odd time signatures
Pattern Length now has options for 3/4, 4/4, 5/4 and 7/8. Look for the 5 Based and 7 Based lengths rather than trying to fake 7/8 by counting steps.
Automation rows
Add a row for any automatable parameter on the channel - filter cutoff, send level, a plug-in control - and sequence it per step alongside the notes. This is how you get the movement without drawing a single automation curve.