A day or so ago, I received email from the Royal Opera House, complete with lovely embedded graphics, about the upcoming premiere of Harrison Birtwhistle's new opera, The Minotaur. There was a link, prominently labeled SEE THE TRAILER.
I clicked the link. At the other end, there's a YouTube video of the librettist, David Harsent, talking. And talking and talking and talking, interspersed with an occasional still photo that I presume to have been taken at rehearsals for the opera. Yes, it's an opera, and the Royal Opera has chosen a talking head to represent the piece in the trailer.
People! It's an opera! Put up some of the music! And even some video from the rehearsals! Whatever you do, do not bore your (potential) audience!!