Tuesday marks the release of Janet Jackson's new compilation album, Number Ones, which packages together two discs worth of her biggest chart-topping singles, including "Nasty," "Any Time, Any Place," "That's the Way Love Goes" and "If." And to celebrate the 34-track album, fans gathered on Saturday in a series of Flash Mobs that took place in various locations in Los Angeles to dance and pay tribute to some of the veteran diva's best dance moves and songs.

The message went out on Janet's official Web site at the end of October that fans could get together in three different locations in Los Angeles. The events were produced by Flash Mob America, who posted the locations of the mobs on its Twitter page throughout the day on Saturday.

Hundreds of people gathered to watch fans, who had rehearsed the day before, at each of the stops, but it was the second Flash Mob stop that grabbed headlines. The mob converged on Los Angeles shopping center the Grove and re-created classic Jackson dance moves to a medley of her hits that included "Rhythm Nation" and "Escapade."

Soon after launching into their performance, the performers realized that Janet herself was watching the mob from a balcony above the fray. When the group turned to acknowledge her, they gave her a raucous ovation, to which she responded with a round of applause and waves to the crowd before disappearing into the building, thus ending the show.

This is only the beginning of Jackson's step back into the spotlight, as she will appear this Wednesday night on an ABC News special in her first prime-time sit-down interview since the death of her brother Michael in June. In the interview, she says that she blames Dr. Conrad Murray, Michael's personal physician, for his death.