The shrewish, often vulgar and always entertaining female folk duo Birdcloud is on the bill tonight at Main Street Live. We won’t list the titles of some of our favorite songs by these ladies; suffice to say they’re aces of raunchy humor. And don’t forget Don Coyote, who will be doing their ramshackle rockabilly thing, otherwise known as “campfire punk,” with a washboard no less, so you know it’s good.