Beyoncé's Alter-Ego Tops The Charts: Wake-Up Video

The lives and careers of pop stars can sometimes be very fleeting. Pop music is a cruel mistress who can sometimes declare things here today and gone today, with few second chances available for those who slip. But on the opposite end of the spectrum, there are some artists who simply cannot be destroyed, who transcend labels and are free to experiment with whatever they fancy. Beyoncé is certainly the in the latter category, as she has racked up hit after hit both as a solo artist and as a member of Destiny's Child. Her most recent album, the split-personality-concept-exploration I Am ... Sasha Fierce, is her best and boldest work yet, and on this day in 2008, it debuted at the top of the Billboard album chart.

I Am ... Sasha Fierce is Beyoncé's third solo album and most certainly her strangest. Broken up into two discs (one representing herself and the other depicting the outlook of her vaguely futuristic cyborg alter-ego, the titular Sasha Fierce), it explores a cavalcade of styles and genres that all manage to have that fundamental Beyoncé twist. The "I Am..." disc is excellent by itself, with anthemic torch songs ("Halo"), mysterious mid-temp numbers ("If I Were a Boy") and plenty of futuristic sounds ("Satellite"). But it's the second disc (titled "Sasha Fierce") that really blows the doors off. There's the signature hit "Single Ladies (Put a Ring On It)," the rocking "Sweet Dreams," the stuttering "Video Phone" and the trippy, head-nodding "Diva," which twists Lil Wayne's "A Milli" into a girl power anthem.