“How Long” by 1970s British rock group Ace was the band’s highest charting hit, reaching #3 in the U.S. It had a slow, smoky groove like another Brit band hit, the Climax Blues Band’s “Couldn’t Get It Right.” It’s been kept alive not only by frequent airplay, but by a plethora of covers. From soul songster Bobby Womack to country chanteusse Barbara Mandrell to rock royalty Rod Stewart. The song lends itself to a voice that’s rough like sandpaper, yet smooth as satin. All of the notable covers do it justice, but Ace’s version remains ace.