Between them, you’ve definitely heard the work of composers (and brothers) Harry and Rupert Gregson-Williams in film and TV projects such as “Wonder Woman,” “The Crown,” “The Chronicles of Narnia: The Lion, the Witch and the Wardrobe,” “House of Gucci,” “The Alienist,” “Catherine the Great” and a large swath of the Adam Sandler oeuvre. But only recently have they decided to join forces to become a double-threat, on HBO’s recently renewed, turn-of-the-century hit “The Gilded Age.”However, this series is not their first duo effort.