Britney Spears [ tickets ] surprised the crowd at the nightclub Rain--located in the Palms hotel-casino in Las Vegas--by playing a 30-minute set.

According to published reports, Spears and a group of dancers on Sunday (9/14) at about 1 a.m. performed three songs from Spears' forthcoming album for a crowd of about 1,800.

Spears' as-yet-untitled new album reportedly is complete, but no release date has been announced.

Madonna [ tickets ] appears on "The Oprah Winfrey Show" on Tuesday (9/16) to promote her new children's book, "The English Roses," and her latest CD, "American Life."

"The Very Best of Sheryl Crow [ tickets ]," a career retrospective that features 14 previously released tracks plus two new songs--the Cat Stevens cover "The First Cut is the Deepest" and the original "Light in Your Eyes"--is scheduled for release on Nov. 4.

Singer-songwriter Anastacia [ tickets ] will serve as the spokesperson for Lifetime Television's annual "Stop Breast Cancer for Life" public-awareness campaign.

Anastacia announced she had breast cancer in January, and recently underwent treatment for disease.

A new U.S. Postal Service commemorative postage-stamp bearing the image of country legend Roy Acuff [ tickets ] was unveiled at a ceremony at Nashville's Grand Ole Opry on Monday (9/15). The stamp will be available at U.S. Post Offices nationwide starting on Tuesday (9/15), according to a press release.