The Jog/Scrub Wheel and SCRUB button can be used to navigate through the project, which is useful for a number of transport tasks. Simply turn the dial to use it. The following Scrub modes change the behavior of the Jog/Scrub Wheel.
Audio tracks are normally played back at their original speed. If you would rather hear them at double speed, choose Logic Pro > Preferences > Audio > Drivers, and set Maximum Scrub Speed to Double in the pop-up menu.
Note: You can also use the SCRUB button for Pause functionality.