What stage persona did Beyoncé use for the second disc of her 2008 album?

Beyoncé used the stage persona Sasha Fierce for the second disc of her 2008 album.

I Am... Sasha Fierce, her third solo studio album, was structured around two contrasting identities. The I Am... disc focused on more personal and vulnerable material, while the Sasha Fierce disc emphasized confident, energetic performance songs.

Beyoncé explained that Sasha Fierce represented a more fearless alter ego that emerged during performances. The concept gave the album a deliberate contrast between the private person and the powerful stage character, although Beyoncé later said she had retired the persona.

The character is sometimes mistaken for a separate recording artist or for a nickname used throughout Beyoncé’s entire career. Sasha Fierce was specifically associated with the 2008 album era and its performance-focused material. Songs connected with that side include “Single Ladies (Put a Ring on It),” “Diva,” and “Video Phone.”