You can create new lanes, and set corresponding Lane parameters, in several ways.
Create a new lane
Select a lane by clicking one of the names shown.
The selected lane is highlighted.
Choose Lanes > Create Lane (default key command: Option-Command-N).
A new lane is created. The original lane, and all subsequent lanes, are moved down. The new lane parameters are identical to those of the originally selected lane.
Adjust the parameters of the new lane in the inspector.
Create one or more specific lane types
You can use the Auto Define feature to automatically create lanes for specific event types in your project.
Choose Auto Define from the Lane Set pop-up menu (or use the Toggle Auto Define key command, default assignment: Control-A).
Open the Event List window, then click the events you want to create new lanes for.
The clicked events are added as lanes in the Lane Set.
Repeat the second step to add more event types to your Lane Set.
If the Lane Set already contains a matching lane type (for a particular note pitch, as an example), Logic Pro will not create a superfluous lane. The existing lane is moved into the visible area of the Step Editor in this situation.
Note: Make sure that you deselect Auto Define immediately after completing your input.
Create lanes for all event types in a region
Select the region.
Choose Lanes > Create Multiple Lanes (or use the corresponding key command).
In the dialog that appears, click the All button to confirm that you want to create lanes for all types of events in the region.
Tip: It’s a good idea to create a new Lane Set before creating a group of new lanes. For more information, see Use Lane Sets.