Eclipseverse: One thousand years ago, long before six young mares took up the Elements of Harmony to save Equestria, the royal sisters faced an insidious foe who threatened to cast his shadow across all the land.
Now, the poet Pinkamena Diane Pie and her friends have put together a show to tell that tale as Equestria has never heard it told before. The stage is set, the actors are ready, and the musicians are prepared to unleash the first rock-opera based this dark period in Equestrian history ever produced.*
That's assuming, of course, that everything goes as planned.
* Based on original music by The Protomen, from their album, "The Father of Death".