Beyonce struts back onto world stage with tour

A power outage at the stadium following her performance, which led to a half-hour delay in the game, prompted her husband of five years to tweet: "Lights out!!! Any questions??"

Music's power couple, Beyonce and Jay-Z, were ranked No 18 and No 20 respectively in Forbes' list of the highest-earning musicians in 2012, earning $40 million and $38 million.

On the back of the praise, Beyonce, 31, wasted no time in announcing her world tour.

"The Mrs. Carter Show World Tour," which starts in Belgrade on April 15, includes 20 European cities and more than 20 North American venues. Slated to run for almost one year, a second wave is planned for Latin America, Australia and Asia.

The North America leg starts at the Staples Center in Los Angeles on June 28 and ends in New York on August 3.

But before the tour starts, the singer has a busy schedule, presenting at the Grammy awards ceremony in Los Angeles on Sunday where she is also a nominee.

The notoriously private singer will also open up about her life in a new documentary, "Life is But a Dream," which she directed, that is set to air on HBO on February 16.

The documentary addresses her relationship with her father after he stepped down as her manager, her miscarriage before she had daughter Blue Ivy, and her work in the studio.

"It was really interesting directing and editing myself, seeing all the mistakes that I made and still putting it in the film," the singer told reporters last week.

The documentary also features rare footage of her 1-year-old daughter who has been shielded from the public.

"My daughter has changed me and changed my life, and has given me so much purpose. I feel like this movie .. it's very necessary and I think it shows a human side," she said.