As this volume of Billboard's continuing series illustrates, Billboard Top Hits: 1981 covers a year of considerable flux in pop radio ? where hits like Kool & the Gang's "Celebration" rode in on the last remaining fumes of the disco era, Dolly Parton's "9 to 5" and Juice Newton's "Queen of Hearts" heralded country's increasing encroachment into the mainstream; even reggae found a place on the charts thanks to Blondie's classic cover of "The Tide Is High." Other notable hits: Kim Carnes' "Bette Davis Eyes," Rick Springfield's "Jessie's Girl" and Olivia Newton-John's "Physical."