I like how they have chosen this classical piece featured in the scene in the sixth episode.
https://www.youtube.com/watch?v=6HGpqcBdntwIts from Handel's famous opera Serse (Xerxes) set in Ancient Persia about 470 BC and is very loosely based upon Xerxes I of Persia; the piece featured in the series is opening aria, "
Ombra mai fu", sung by Xerxes to a plane tree.
But what is interesting is that Xerxes was one of those kings (Darius, Cyrus, Artaxerxes) of Achaemenid dynasty that worshiped
Mithras (Zoroastrian pantheon) as many historians presume based on some material historical evidences.
This is an inscription in Susa Palace made after successful restoration by Xerxes and Artaxerxes:
"...May Ahuramazda, Anahita, and Mithra protect me against all evil, and may they
never destroy nor damage what I have built."Do you think it was a random choice or it was planned?