When you add an audio file without tempo information to a cell, Logic Pro analyzes the tempo of the audio file. You can edit the tempo information using the bar loops and copies them to the next empty cells to the right.
Extract Best 4-Bar Loops: Determines the best four-bar loops and copies them to the next empty cells to the right.
Extract Best 8-Bar Loops: Determines the best eight-bar loops and copies them to the next empty cells to the right.
Extract Best Loops of Any Size: Determines the best loops of any size throughout the audio file and copies them to the next empty cells to the right.
To consider all musically meaningful positions for potential loop start points, not just downbeats, make sure Limit Loop Points to Downbeats is turned off in the Extract Loops submenu.
Loop extraction is disabled if:
The cell is empty or contains multiple regions.
The region in the cell is shorter than two bars.
Flex & Follow in the Cell inspector is turned off.
The cell contains Apple Loops or Extract vocal and instrumental stems with Stem Splitter.
In the Live Loops grid in Logic Pro, Control-click the audio cell, then choose Stem Splitter.
In the Stem Splitter dialog, checkboxes for all four stems (Vocals, Drums, Bass, and Other) are selected by default. Deselect the checkboxes for any stems you do not want to extract.
Click Split.
A summing stack is created below the track with the selected audio cell. The subtracks of the summing stack contain cells with the extracted stems. You can solo individual stems using the Solo buttons in the subtrack headers, and you can move, copy, or edit each part in the same way as any audio cell.
Download the guides:
Logic Pro User Guide: PDF