Britney Spears made 5,000 fans very happy today, performing a concert for "Good Morning America" at the Bill Graham Civic Auditorium in San Francisco.
Singing three songs from her new album "Femme Fatale," Spears danced on stage, wowing the packed auditorium.
The new album -- her seventh -- comes out on Tuesday.
Watch "Good Morning America" Tuesday to see the full concert and hear Spears' special announcement.
Spears, 29, greeted the crowd in a silver sequined body-suit, and sang "Hold It Against Me."
Her adoring fans, some of whom had been camped out all night, held signs and screamed for the pop star.
"I thought it was amazing. She was really great," said Sarah Ammann, a fan from San Francisco.
"She's the ultimate performer. She's definitely back," added Alicia Kennon of Brentwood, Calif.
Spears changed costumes and surprised the crowd by coming out of a speaker, dancing and singing "Big Fat Bass."
Wearing a black leotard and a black officer hat, she climbed on speakers that were set up on the stage, to cheers from the concertgoers.
For her last song, Spears sang "Till The World Ends," wearing a black leotard spotted with flashing red lights and fishnet tights.
CLICK HERE for photos from the concert.
Spears closed the show standing on a metal structure facing to the crowd while a fireworks-like explosion lit up the stage. As she left the stage, fans screamed and cheered for more.
"I thought it was good, she looked really good and the crowd was into the last song," Nick Casey of Brentwood said.
Even though free tickets to the show sold out in 14 minutes when they were made available last week, fans were lined up outside the venue and tried to get in to see the star.
"GMA" anchor Robin Roberts described the concert as "phenomenal," saying "the energy, the people, the dancing the music, Britney -- it was tremendous!"
Tune in to "Good Morning America" on Tuesday to see the concert and more from behind the scenes at the Britney Spears concert.