Lita Ford writes in her book Living Like A Runaway about something she discussed a couple of years back in a session with Bravewords.com. Ford maintains that Robert Plant attended a Runaways concert in 1975 and, after the gig, offered her the chance to join Led Zeppelin if she was willing to play bass. She admits that Plant might have been tipsy of just kidding, but maintains she thinks he was 'dead serious' about the idea. The timing of the encounter does match-up with the period that the future direction and lineup of Zeppelin was uncertain.
ConsequenceOfSound.com
