Rival Sons are influenced by '70s riffmongers ranging from Led Zeppelin to Foghat, but they’re not anchored to that period; theirs is more of a modern retro sound. Head Down starts out hot and rarely lets up on the gritty, bluesy guitar licks, hooks, airtight drums, and pounding, straight-ahead bass lines. The real clincher is lead singer Jay Buchanan, whose voice is a shot of power and adrenaline in the vein of Chris Cornell or Chris Robinson. Head Down is mostly heavy, air-guitar rock, as in the swaggering “Keep on Swinging” and “You Want To.” Rival Sons head for epic on the 13-minute, two-part psychedelic opus “Manifest Destiny,” complete with an extended guitar solo and Native American history narrative. But they mix it up, too, with the sunny uptempo pop of “Until the Sun Comes” and “Wild Animal,” the soulful power ballad “Jordan,” and the folky closer “True.” Head Down is a visceral, hard-charging ride.