Key focus
The active item—such as a window, area, track, or scene—is said to have key focus or be focused. Although you can select multiple items, only one item can have key focus at a given time.
In the Logic Pro main window, you can give different items key focus by clicking the background or title bar of the window, by clicking the item, or by using a tool in the window or area. When you select multiple tracks, the first selected track is the focused track.
You can tell that an item has key focus by its appearance. For example, the title of the window with key focus is black (the titles of other open windows are gray); inside a window, the area with key focus (such as the Tracks area) is bordered by a blue frame; and the track number of the focused track appears highlighted in gray on the left edge of the track header.
Many key commands will function only when an item has key focus.