A couple of months back (story), Cliff Williams said he would probably retire at the end of AC/DC's Rock Or Bust tour. That decision is one the group's bass player is sticking with. Williams took the stage for the last time with AC/DC in Philadelphia Tuesday (9/20), saying afterwards, 'It's time for me to step out, an that's all'. Williams became the AC/DC bass player in 1977 and made his record debut with the group on the followin year's Powerage album. His departure leaves Angus Young as the only long-term member of the band.