Looking back, Cheap Thrills isn't quite the masterpiece critics hailed it as when released in the summer of '68. Nevertheless, it is at times an exhilarating listen. What's most striking is how on a handful of tracks the band can be heard inventing the template for heavy metal's throat-shredding singer and hot-licks guitarist tandem. Page-Plant, Tyler-Perry and Osbourne-Iommi all owe a little something to Janis Joplin and James Gurley (who were lovers as well as bandmates). To hear this pair at its hardest rocking, check out "Combination of the Two" and "I Need a Man to Love."