Janet Jackson Unsuspecting shoppers hitting The Grove, an outdoor mall in the heart of Los Angeles, got a huge surprise when Janet Jackson made an appearance to promote her upcoming 'Number Ones' album Saturday (Nov. 14). "There is a rumor that Janet is going to be at the 2nd Flash Mob at 2pm @ The Grove!" Jackson's web team hinted earlier on her Twitter page.

While Jackson stood over the stunned crowd on a nearby balcony, a flash mob of dancers performed a routine to a melody of her hits. Although Jackson did not perform, the 42-year-old waved to the hundreds of screaming bystanders, while a photographer stood next to her and took pictures. After the short appearance, fans chanted her name long after she disappeared behind closed doors.

Jackson is getting back into the swing of things since the untimely death of her older brother Michael on June 25. As a tribute to her brother, Jackson performed their duet 'Scream,' at this year's MTV Video Music Awards alongside footage of him from the original music video. She will also open this year American Music Awards and sit-down for an ABC interview about Michael's death, which airs Nov. 18 on ABC. "Its still so difficult for me," she said in an interview snippet already making rounds. 'Number Ones' hits stores tomorrow (Nov. 17).

Watch the video after the jump.