I am unfortunately one of those people that never saw the live performance. Seeing something live helps you appreciate the most minimal staging. So I have nothing to compare and found this an obstruction when concentrating on the music and the story.
Based on a play" Iphigenia in Tauris" by Greek dramatist Euripides this presentation in four acts was composed by Christoph Willibald von Gluck (July 2, 1714 - November 15, 1787).
Even if this is your first foray into the presentation it would be good to know a little bit of the background so you he would have an idea of what the people are trying to say or do. It's very difficult with this particular staging to just dive right in and understand what is going on.
At the beginning of the Trojan War the goddess Diane had turned the wins against Agamemnon. To satisfy the goddess Diane Agamemnon had to sacrifice his daughter Iphigénie. However Diane saved Iphigénie and delivered her to Tauride, where Iphigénie served the enemy Scythians as Diane's high priestess. The first act is 15 years after the incident and takes place during a storm that battered Diane's temple at Tauride.
You can look up the details ahead of time and then follow the presentation. I have to admit I needed the English subtitles. Maybe later I will not need them.