The late Queen singer’s composer collaborator Mike Moran once said of him: “Very few people can sing like Freddie Mercury. He’s one of the most unique performers I’ve ever had the fortune to work with. Freddie’s an amazing vocalist and he’s got immense range. Got great control over his voice, great phrasing.” One occasion when Moran was particularly impressed with Freddie’s singing talent was when he collaborated with Montserrat Caballé on smash hit popera track Barcelona…