Complex sentence: The "Merrie Melodies" intro tune was heard, and then the whole venue went dark while the theme from "The Equalizer" was played over the PA system for a few minutes before the band then started the first song of the set.
Split into simpler sentences: The "Merrie Melodies" intro tune was heard, and the whole venue went dark. Then there was an instrumental song (for the warmup shows, they used the theme from The Equalizer) playing for a little while, before the band started the first song of the set.