Its follow-up, In the Zone (2003), sold nearly three million, partly on the strength of the hit single “Toxic.”Spears’s subsequent studio albums suffered diminished sales but remained major events in the pop music world. The electronic-infused Blackout (2007) found her in a self-reflective mood; Circus (2008) featured her first Billboard number-one single (“Womanizer”) since her debut; and Femme Fatale (2011) was her most up-tempo dance-oriented offering to date. Britney Jean (2013) was characterized by Spears as being highly personal, but it was criticized for obscuring her voice with synthesized effects. However, Glory (2016), her ninth studio album, was considered a return to form for the singer.
