I'm guessing you mean via the controller and not using a mouse and keyboard? If you so, you need to first save a folder on the external hard drive and name it what you want. Then, open maschine and save the new project (beat) in the new folder you created on your external hard drive. Now, when you start your beat you can save to that folder form the controller periodically as you continue to make your beat from the controller by holding SHIFT and pressing the button labeled 'ALL