Disco orchestras are a rare species, like the golden-winged Warbler or the Loch Ness Monster. Actually, let’s face it: there’s only one true specimen left on Earth right now and they come hot out of Brooklyn by the name of Escort. They’ve appeared in Chicago a few times in recent years, with different arrangements each time. This time they’re bringing the full band experience in all its stringed & horned goodness. Rumor has it that they have some new material to unleash as well. When you add a Thibault late night disco set to follow the Escort show, this night of music can’t get much better. With an abundance of musical options this Friday, Concord Music Hall is still one of the best places to be — the elusive disco orchestra in its natural habitat is something not to be missed.