Bohemian Rhapsody is proving to be box office dynamite (with a laser beam?). Twentieth Century Fox’s foot-stomping biopic about the influential British rock band Queen is on track to sell an estimated $50 million in tickets at 4,000 theaters in the U.S. and Canada this weekend, far exceeding expectations and easily dethroning Halloween as the No. 1 film in North America. Starring Rami Malek (Mr. Robot) as Queen’s charismatic frontman, Freddie Mercury, Bohemian Rhapsody will notch the second biggest opening for a music biopic ever, behind 2015’s Straight Outta Compton ($60.2 million). Heading into the weekend, the film had been...