I left a big space at the beginning of my very first Pro Tools session in case I wanted to add an instrumental intro later. Now that I've dismissed the idea of an intro, I'd like to lock all the tracks together and slide them to the beginning of the session. I tried highlighting the whole shebang hoping that I could slide it backward with the Grabber tool, but I find that I lose the highlighting as soon as I grab at it. What's the proper way to accomplish this task?