Los Angeles Times

"No Air"

By Jordin Sparks and Chris Brown Axl can't perform with no air, which is why he owns a $75,000 pressurized oxygen pod called a CVAC that he uses to refresh his body and is reported to duck offstage during shows to use an oxygen mask between songs. It's tough to say how he would handle the duet format, though. We've always pictured him as more of a solo karaoke type.Getty Images