Anyone who’s ever sat through one those Ozzy solo sets that leads up to a big Black Sabbath climax at an Ozzfest will appreciate the logic of this all-covers disc: without “Iron Man” and the rest of Sabbath’s catalogue, the Ozman’s own songbook is mighty thin, give or take a “Crazy Train” or two. Of course, fans have every reason to be cynical about this single-disc repackaging of material from the Prince of Darkness four-CD box warmed over with a couple of outtakes that were likely left out for good reason. Not even guest appearances by Jerry Cantrell, Leslie West, and Ian Hunter can make up for a “Go Now” that’s thoughtlessly overworked with strings and background harmonies, or Ozzy’s odd robotic delivery of the ballads “Woman” and “In My Life.” (Is he sounding out the words as he reads them off a Teleprompter or what?) “Rocky Mountain Way,” “Mississippi Queen,” and “21st Century Schizoid Man” are more his speed — slow, sludgy, and granite-hard in spite of too much studio goo. Give Ozzy, Sharon, or whoever’s making the decisions here credit for a “War Pigs” reworking of “For What It’s Worth,” and let’s just say Under Cover’s “Sympathy for the Devil” puts Axl’s to shame, even if Ozzy delivers “What’s my name?” in a tone that suggests he doesn’t know. As that chorus of what sound like a bunch of Kellys in the Mott cover repeat over and over again until you’re certain Ozzy’s just not hearing them, “All the young dudes/Carry the news.”