To a fan and to a friend, there was always something rather unknowable about the air with which Freddie Mercury carried himself. He was, of course, searingly present in every sense of the word. You couldn’t walk into a room and somehow miss the man with the moustache, similarly to how you couldn’t turn on a record and overlook that powering vibrato. The whole point was that Mercury was entirely unmistakable, like most frontmen are, but with him,…