There's about to be a lot revealed about Lady Gaga in a new blockbuster biography about the Bad Romance singer that hits shelves on Tuesday, September 14 - and only RadarOnline.com has exclusive excerpts before the book's release.

EXCLUSIVE PHOTOS: Lady Gaga Before She Was Famous

Among the many interesting things about Gaga in Poker Face: The Rise and Rise of Lady Gaga is why she canceled her headlining tour with Kanye West last summer.

"He's a grade-A disaster, a mess. If his name is on it, no one will touch it," a source inside West's camp told author Maureen Callahan.