Fans waiting to buy copies of Prince's highly anticipated new album, "3121," were greeted early Tuesday with something even better — a surprise performance by Prince himself.

Wearing a white top hat and jacket, the pop-funk maestro launched into a punchy set of songs at midnight at the Sunset Tower Records in Hollywood.

Fans screamed, dancers onstage shimmied, Prince broke out his frenzied guitar playing, and longtime collaborator Sheila E joined in on percussion, according to a Tower press release.

"It was an impromptu decision. He lives in L.A.," said Serena Gallagher, publicist for Prince's label, Universal Motown Records.

About 500 fans who received special purple wristbands at 10 p.m. packed into the store, leaving others outside in the rain.

Prince performed classic hits such as "Let's Go Crazy" and "Purple Rain" and invited attendees onto the stage for a dance contest.