As the Rolling Stones' most ambitious album since Some Girls, Undercover is a weird, wild mix of hard rock, new wave pop, reggae, dub, and soul. Even with all the careening musical eclecticism, what distinguishes Undercover is its bleak, nihilistic attitude -- it's teeming with sickness, with violence, kinky sex, and loathing dripping from almost every song. "Undercover of the Night" slams with echoing guitars and rubbery basslines, as Jagger gives a feverish litany of sex, corruption, and suicide. It set the tone for the rest of the album, whether it's the runaway nymphomaniac of "She Was Hot" or the ridiculous slasher imagery of "Too Much Blood." Only Keith's "Wanna Hold You" offers a reprieve from the carnage, and its relentless bloodletting makes the album a singularly fascinating listen. For some observers, that mixture was nearly too difficult to stomach, but for others, it's a fascinating record, particularly since much of its nastiness feels as if the Stones, and Jagger and Richards in particular, are running out of patience with each other.