IMAGINE (2LP/CLR)One of John Lennon's finest post Beatles recordings, IMAGINE displays the varied voices that made the former mop top one of pop's most profoundly engaging and perplexing figures an idealist one minute, a cynic the next. Although Lennon's gorgeous title track has become a deserving anthem for peace, the caustic "How Do You Sleep?" directed at Paul McCartney would hardly seem like a beatnik's olive branch. These ten songs also see Lennon searching for