Roberta Flack

In this classic-rock-dominated city, the likelihood that a request for “Feel Like Making Love” will be honored on the air with Roberta Flack rather than Bad Company hovers around 1 percent. Neither song is any good, but at least Flack’s ting-ta-ta-ting-ing come-on is lightly sensual rather than a thundering cliché. Reviewing the 1975 album that takes its title from that song, Stephen Holden declared in Rolling Stone that a beautiful voice “just isn’t enough.” In the quarter century since Flack’s come-hither hit, a beautiful voice has actually proved to be the stand-alone explanation for several careers — notably Mariah Carey’s — while Flack has faded from view. Yet on her best work, Flack’s singular voice was never the only attraction; find another soul singer able to draw out Leonard Cohen’s “Suzanne” to a ludicrous nine-minutes-plus without sounding ridiculous or melodramatic. And though Hugh Grant’s wincing take on Flack’s “Killing Me Softly” in About a Boy rightly emphasized that song’s risible limpness, it wouldn’t have been funny if the original didn’t stick to the subconscious like molasses. Besides those signature songs and her hypnotic soul bolero “The First Time Ever I Saw Your Face,” Flack, who never stopped recording steadily, has plenty of pre- and postdisco R&B to draw from in concert. But what she’ll bring to the table at the Ameristar this weekend is something increasingly hard to come by: class.