“At the time Blackout dropped, it sounded like it came from the future—a dystopian and warped future, but nevertheless interesting. Pop radio had remained steeped in the pop-R&B influences that had also driven Spears’ music until then: The top songs of the year were Beyoncé’s “Irreplaceable” and Rihanna’s “Umbrella,” both beautifully sung grooves. Blackout offered crunchy beats that sounded like they were coming from a broken computer, classic dubstep wobbler effects, and Spears’ voice intentionally distorted in every way possible. Whether Spears could sing didn’t matter; her producers played her like an instrument.”
“That’s one of the more practical reasons that the opening line of the first song, “Gimme More,” is brilliant: “It’s Britney, bitch.” Instantly quotable, yes, but also a mere disclaimer—yes, this is actually Britney Spears. She is present and accounted for before her recognizable breathiness morphs seamlessly into a bass-toned, male sounding gurgle, then into a chorus of Britneys and back again during the repetitive chorus of the song.”
—Jennifer Armstrong, Billboard (2017)