Photos: Madonna's U.S. Tour Opener in Philadelphia
Madonna performs live at the opening U.S. date of her MDNA tour in Philadelphia on August 28, 2012.

Welcome to the Wednesday, Sept. 5 edition of "The Beat," Billboard.com's daily music news show, featuring host Jonathan Brooks running down the latest music news -- who's making headlines and who's topping the charts.

In today's episode, J.B. dishes on the latest Hot Tours ranking (which Madonna topped), Nicki Minaj's pro-Mitt Romney rap, the news that K-pop sensation Psy was signed by Bieber's manager Scooter Braun, and Rita Ora's U.K. chart success. He also remembers Starship guitarist Mark Abrahamian, who died of a heart attack Sunday.

Be sure to come back to Billboard.com each weekday afternoon to watch a fresh episode of "The Beat."