Guns N' Roses had a surprise in store for their headlining set at Rock in Rio last night: Axl Rose and company played "Estranged" for the first time in 18 years. You could say Guns N' Roses have been "estranged" from the Use Your Illusion II song: the last time GN'R played it, a dude with an Afro and top hat was playing the guitar solo, The Spaghetti Incident? hadn't happened yet, and no one had heard of DJ Ashba, Buckethead, and Richard Foetus. The last performance of "Estranged" was June 26, 1993 at Munich's Olympiastadon, when Rose was a much, much better singer.

The zombie GN'R lineup takes some heat for being a bunch of guys not named Slash, Duff, and Izzy, but they do an amazing job of reproducing the track, from the opening piano notes to the dolphin's call guitar solo; it's as if they've spent the last 18 years rehearsing the complex song. But then there's Axl. Maybe it's because he's unfamiliar with the track, or maybe his voice is showing nearly two decades of wear, but his

Sex! Now that we've got your attention, we'd like to tell you that 92 percent of the biggest songs of 2009 were about sex. The Atlantic Wire tracked down a study published in Evolutionary Psychology that analyzed the 174 songs that hit the Top 10 on Billboard's singles chart two years ago for evidence of "reproductive messages." Such messages could be overt (references to "genitalia"), boastful (notes about "sexual prowess"), romantic (lyrics about "fidelity assurance"), bummed out ("rejection"), or literal ("parenting"). Researchers identified 18 such categories, then cued up the Kenny Chesney and Lady Gaga and started fanning themselves.

In addition to proving the somewhat obvious point -- pop songs are often about sex? Why we never! -- the study tracked a few somewhat obvious trends. Country songs mostly referenced commitment, parenting, rejection, and fidelity assurance while R&B tunes were frequently about sex appeal, resources, sex acts, and status.

The researchers also looked

Just when you thought Tupac Shakur's musical vaults were completely emptied by the countless albums released after his death, another unreleased track suddenly emerges. However, this could be the strangest song leak in music history: TMZ reports that video of 2Pac performing some never-heard verses in 1991 has emerged... on a sex tape starring the rapper. Interscope is going to need something much stronger than "Parental Advisory: Explicit Lyrics" stickers to release this track.

TMZ has a rundown of what transpires on the tape -- The Amp hasn't seen the video -- and without getting too deep into the sordid details, the action features 2Pac, groupies, oral sex, and a cameo by Digital Underground's Money B. (Anyone who's ever heard Digital Underground's "Freaks of the Industry" knows this type of behavior was pretty routine.) If you can get past the initial shock of a 20-year-old 2Pac sex tape existing, TMZ's claim that Shakur was "singing along and dancing, wiggling his hips" to "an

The Immortal World Tour, the $57 million Cirque du Soleil spectacular featuring the music, imagery, and choreography associated with Michael Jackson, premiered this weekend in Montreal, and today the late singer's estate confirmed its soundtrack will be released in time for Black Friday. Immortal will be the third posthumous Jackson album, following This Is It, which arrived in conjunction with the documentary of the same name in 2009, and Michael, a 2010 disc of mostly unheard material cobbled together after MJ's death.

Billed as "the new album from Michael Jackson," November 21st's Immortal will not actually feature any "new" Michael Jackson songs per se -- the deluxe double disc and single disc versions of the album consist of "Immortal versions" of the star's hits arranged by Jackson's longtime collaborator Kevin Antunes, including "Wanna Be Startin' Somethin'," "Man in the Mirror," and "Bad." A press release boasts the album also includes "an alternate take on the Jackson 5's