Ian Mitchell, bassist for the Bay City Rollers, has died at the age of 62, according to a post on the group’s Facebook page.With hits including “Saturday Night” and “Bye Bye Baby,” the tartan-clad Scottish group were a pre-punk 1970s phenomenon in the UK and enjoyed several hits in the US.“We are deeply saddened by the news of Ian Mitchell’s death,” the brief message reads. “Our thoughts and prayers are with his wife Wendy, their family and friends.