House, techno, and disco collide Thursday as a trio of DJs keep the dance floor packed for “Flashing Lights” at U Street Music Hall. $8; 10 PM.
The Made in Hong Kong Film Festival continues at the Freer Gallery with 1978’s The Contract, a classic satire of the entertainment industry by the Hui brothers. Free; Friday 7 PM, Sunday 2 PM.
Curious about contra dance? Learn the ropes at Glen Echo Park Spanish Ballroom (7300 MacArthur Blvd., Glen Echo; 301-634-2222) with a lesson followed by a dance to live music on Friday. And if you decide you’re too clumsy, or simply too darn hot, there are always the rides for alternative entertainment. $9; 7:30.
The Rosslyn Outdoor Film Festival continues Friday at Gateway Park with Dumb & Dumber, the comic film that follows the titular pair on a road trip to deliver a piece of lost luggage. It’s part of this year’s “I Love the ’90s” theme—and a great opportunity to turn off your brain and survive the heat. Free; 8 PM.
The Liberation Dance Party continues Friday at DC9, with an open bar from 9 to 10:30. $7.
The Black Cat holds its Indian-dance music night on Friday with a Washingtonian twist—it’s called the “US Department of Bhangra,” and it’s DJed by Beta-G $5; 9:30.
In preparation for Shark Week, the National Aquarium (1401 Constitution Ave., NW; 202-789-2782) is holding Shark Weekend, where visitors can learn about the fearsome species with expert presentations, scavenger hunts, and more. It may not be Jaws, but sometimes life can be just as entertaining as—and a whole lot less dangerous than—fiction. $9 aquarium admission. Satuarday 9:30 to 3:30.
Celebrate National Dance Day on the Mall Saturday with an afternoon of performances by the Washington Ballet, Step Afrika, and more. The event features Nigel Lythgoe from So You Think You Can Dance. Free. 3 PM.
The Frederick Douglass Home Family Fun Festival features music, games, crafts, and a tour of the historic house where the African American leader spent his Washington years, now a National Historic Site (1411 W St., SE; 202-426-5961). Free. Sunday 11 to 3.