Ever wonder what the legendary, and oft-private PRINCE is like when he's not on stage? Well fans are soon to find out. ET confirms that the singer will present his first book, 21 Nights, this fall.

The multi-media book goes behind the scenes of Prince's record-breaking, sold-out 21 concerts in 21 nights at London's 02 Arena in 2007 and also includes 124 full-color, never-before-seen photographs.

"We are tremendously honored and excited by this opportunity to present this lyrical and visually rich book from Prince that captures the spirit and voluptuous sound of his brilliant 21-night residency at the O2 concert hall in London," says JUDITH CURR of Atria Books. "21 Nights is an innovative multi-media book project created by a musical visionary and uncompromising artist, an invitation to experience a side Prince has not revealed until now."