Britney Spears dazzles critics in Las Vegas
Pop star Britney Spears has received rave reviews for the opening night of her Las Vegas residency on Friday.
"Spears stomped into town with a 21-hit salute," wrote Marco della Cava in USA Today, noting the show "artfully melded spectacle with stagecraft".
MTV's Sophie Schillaci highlighted the "larger-than-life production, blaring beats and rapid-fire dance moves".
But the LA Times' Mikael Wood observed: "She was wearing a microphone, though it wasn't clear she was using it."
"The singer appeared to be lip-syncing for the majority of her performance.
"That went for high-energy dance numbers such as Womanizer as well as slower-paced ballads like Perfume," said Wood, who went on to praise the event's "elaborate razzle-dazzle".
"The vast majority of the show was lip-synced," agreed Keith Caulfield in Billboard.
"Only occasionally were any seemingly live vocals heard [and] there was a certain thrill in actually hearing Spears breathing into the microphone - however infrequent."
Despite that, Caulfield praised the "non-stop hits bonanza" and pointed out that the tightly-choreographed Gimme More gave Spears "a moment of Vegas redemption" after her infamously lacklustre performance of the song at the MTV Awards, held in the city in 2007.
Britney: Piece Of Me is named after the 32-year-old's tabloid-baiting hit single from 2007.
A retrospective of her 15-year pop career, the 24-strong setlist includes hits such as Toxic, Scream and Shout, Womanizer and Baby ...One More Time, with only two songs culled from her recent, under-performing Britney Jean album.
Among the crowd on opening night were fellow pop stars Katy Perry, Adam Lambert, Selena Gomez and Miley Cyrus, who posted several pictures of herself enjoying the show on Twitter.
"If you told me I'd be front row and center on @britneyspears opening night 10 years ago I would've never believed you," she wrote.
Others were less enthusiastic, however.
"Her dancing, touted as the show's linchpin, was lackadaisical and - as has become the norm for Spears - reliant on arm movements," wrote Caryn Ganz in Rolling Stone magazine.
"Spears seemed truly frightened," during the number Slave 4U, Ganz said, "remaining safely on a throne, executing minimal choreography while her dancers did the heavy lifting".
"In general, the set design was more imposing than she was," agreed Jon Caramanica in the New York Times.
"Magical things are happening all around her — ornate sets, clever video displays, fiery dancing — but Ms Spears is there mostly to activate memories, to be a souvenir for the eyes."
However, said Hannah Dreier for the Associated Press, the "eye-popping" show kept the 4,500 audience members "on their feet for about 90 minutes".
Dreier added that Spears is hoping to draw a younger demographic to Las Vegas than the usual entertainers in residence - from Elvis in the 1970s to Celine Dion and Bette Midler today.
"She cuts a different figure from the typical Strip headliner," she wrote. "Judging from Friday's show, her fans are more likely to be found at a casino mega-club than in front of a slot machine."
"One could almost make the argument that this show might entertain a non-Britney fan because of its production values, which is likely not the case with other residencies," added Marco della Cava.
"If you don't care for Elton John, not even a $10 million piano would keep you seated for his Vegas hit parade."
Spears is due to perform 50 shows each in 2014 and 2015 at Planet Hollywood's Axis theatre, and casino executives say the run could be extended if it proves a success.
They denied that the star lip-synced throughout the show, saying Spears sang against a pre-recorded track of her vocals to help her through the more physically gruelling parts of the set.