Tempo Track: Extend Left
There is a whole world of work that can be done with a tempo track. The only thing I typically do with tempo is to create a tempo track for audio tracks that I have with no tempo information.
Move the selected tempo point, replacing the previous one
In Logic Pro, Control-click a tempo point, then choose Extend Left from the shortcut menu.
The selected tempo point is moved left to the position of the previous one, which it replaces.
Note: This menu item is not available for the first tempo point.