Start all the cells in a scene: Click the trigger in any of the queued cells or use the Trigger Live Loops key command (Return) to play queued cells at the next quantize start point.
Control-click a cell, choose Playback > Quantize Start, then choose a Quantize Start value from the submenu.
In addition to bar and beat values, you can also choose the following Quantize Start options:
Cell End: If another cell in the same row is playing, the triggered cell starts when the playing cell reaches the end of the loop.
Off: Cells start and stop when you click them, regardless of the Quantize Start value. Note that this can lead to cells playing out of sync.
Global: The cell or scene follows the Quantize Start value of the grid. This is the default setting for cells and scenes, and probably the best choice for most situations.
Click the Quantize Start pop-up menu in the upper-right corner of the grid, then choose Smart Pickup.
The trigger mode in Logic Pro determines how a cell starts and stops when you click the Play/Stop button. Both actions are subject to the Quantize Start value. You can choose three trigger modes:
Start/Stop: Cells start and stop playing when you click them.
Momentary: Cells start playing when you click and hold the pointer on them, and stop playing when you release the pointer.
Retrigger: If a cell is playing and you click it again, it starts playing from the beginning. Cells set to Retrigger can be stopped only by starting another cell or clicking the Stop button in an empty cell in the same row, by stopping the row using the Divider column, or by stopping the entire grid.
Do either of the following:
Select one or more cells, then choose a trigger mode from the Trigger Mode pop-up menu in the Cell inspector.
Logic Pro Instruments: PDF