Select All Lanes

Selects all of the lanes in the Step Editor.

Edit lane parameters in Logic Pro — Apple Support

You can copy, delete, reorganize, and convert lanes and their associated parameters when creating Lane Sets.

Logic Pro Step Editor Overview — Apple Support

The Step Editor is a graphical editor that can be used to create or edit MIDI note and controller data. You can use the Step Editor to view and edit different MIDI event types, shown as vertical beams—or steps—along a timeline within a region.