An all-time vocal performance and a bright spotlight of a Clint Eastwood movie synch gave Roberta Flack her long-overdue breakout hit and first Billboard Hot 100 No. 1.

Roberta Flack, whose smooth, rich, supple and mesmerizing vocals in the 1970 made instant classics of such Grammy-winning hits as "The First Time Ever I Saw Your Face," "Killing Me Softly with His ...