Interpreting other bands' songs isn't part of the rhetoric of heavy metal. It makes the distance between musician and fan too negligible; metal heroes are supposed to be lords of the realm beyond good and evil, not librarian-minded record collectors. Metallica are the exception. Their last tour was a metaphor for rock bloatedness that featured a collapsing light rig, flaming propmen on zip wires and a fake EMS brigade. After a contrived disaster took place, the band scaled back to reality, huddled around some small amps and started the serious part of the show: the covers.

A few songs released in 1984 ("Am I Evil?," "Blitzkrieg") first proclaimed Metallica's goofy fandom for obscure British metal bands. Those tracks, as well as all of 1987's Garage Days Re-Revisited EP, scattered B sides and eleven new covers make up the band's new double-disc set, Garage Inc. It includes few obvious choices. Black Sabbath's "Sabbra Cadabra," OK, but nearly a third of the album is an homage to what was once nerdily called NWOBHM (new wave of British heavy metal) – bands like Sweet Savage and Dlamond Head. It was the fast, minimalist, needling relay-riffing of those bands, as the liner notes from Rolling Stone senior editor David Fricke explain, that were the primary influence on Metallica. Otherwise, good for Metallica for intuiting that Nick Cave's "Loverman" sits somewhere on the perimeter of metal (that baritone, that fall-of-man fixation), as does Bob Seger's "Turn the Page" (that hair, that epic nihilistic gloom on the subject of tour-bus depression).

Gloriously hard as the album is, you can't miss Metallica's good-natured side coming through. Among its charms, beside its floppily casual song endings, is that the band doesn't even try to be inclusive, to tackle a different band in each track. You will just have to hang in there for their obsessions with Diamond Head (four tracks, from the same album), Discharge (two), Motorhead (four, including a version of "Overkill" with a sloppy-as-hell missed cue) and the Misfits (three). An acoustic Lynyrd Skynyrd track with a harmonica solo ("Tuesday's Gone")? A sicko, dumb-as-a-stump Anti-Nowhere League song ("So What")? They're all acts of love.

“1999”

“I don’t consider myself a great poet,” Prince told Rolling Stone. “I just know I’m here to say what’s on my mind.” In the case of the apocalyptic party anthem “1999,” he was worried about then-president Ronald Reagan’s foreign policies. The song’s melody is based on a riff borrowed from the Mamas and Papas’ “Monday, Monday,” and Prince originally envisioned the first verse with three-part harmony but later split the vocals between himself and members of the Revolution. Because Warner Bros., with whom Prince was locked in a contractual battle, owned the original’s masters, Prince rerecorded the song and appropriately released that version in 1999.