Paul McCartney’s 1980 album saw him recording all the instruments, using synths as a means of musical experimentation—“Summer’s Day Song” is an unearthly electronic lament in the vein of David Bowie’s Low—and accidentally creating the irresistible future funk masterpieces “Temporary Secretary” and “Coming Up” along the way. There are more traditionally rocking tunes, too: “Nobody Knows” and “On the Way” would have fit on his early-‘70s solo albums, and “Waterfalls” is a particularly devastating example of a McCartney heartbreak ballad.