Robert Plant, who scored most of his major points in Led Zeppelin by unbuttoning his shirt and squealing ooooh at appropriate junctures, sounds on his sixth solo album, Fate of Nations, as if he's searching for more viable and eloquent means of expression. In fact, "Calling to You," the opening cut, which crosses "Kashmir" with "Dancing Days," almost ceremoniously attempts to shake the Led out. But rather than trying to cash in on past career peaks, Plant may be evoking the most excruciatingly painful moment of his personal life, the tragic 1977 death of his young son Karac while the singer was in the thick of one of Zep's notoriously hell-raising tours.

Never previously alluded to so obviously on record, the child's very tangible spirit, invoked in the devastating "I Believe," hovers over most of the other songs on Fate. Sensitively accompanied by bassist Charlie Jones (who is Plant's son-in-law), the chimingly inventive guitar of Kevin Scott MacMichael and the plaintive violin of Nigel Kennedy (studio guests also include Richard Thompson and Clannad's Maire Brennan), Plant's always incredible voice finds a new temperature for sex ("29 Palms" — have mercy!) and plumbs new dimensions of strength and of sorrow.

Plant's technical achievements alone attest that some of rock's greatest performers are, like any legendary vintage, only improving with time. But his brave efforts to confront the unfathomable demonstrate in more important ways how even the hardest rock can occasionally yield new meaning.

“The A Team”

This debut track from the then-20-year-old British singer-songwriter has a dark story behind it. Sheeran says he culls songwriting inspiration from "viewing other people's situations," which, for the heroine in "The A Team," involves drug addiction and prostitution that began as a teen. Sheeran paints the woman's trials with haunting imagery such as "But lately her face seems/Slowly sinking, wasting/Crumbling like pastries." "I did a gig at a homeless shelter, [and the song] is about one of the women there. It's her story," he said.