If you're under 25 you might find this tough to accept, but back in the '70s and '80s people used to actually pay good money to go sit in a tent, and watch a laser light show that was inevitably choreographed to Dark Side of the Moon. Of course certain pharmacological enhancements were usually necessary to get the full effect.
Now for $25 you can recreate the same experience at home, (chemical enhancements not included), using the Red Hot Laser Light Show. What used to take a whole truckload of gear, now runs with just four AA batteries, projecting spheres, lines, and shapes across your walls and ceiling. A built in microphone picks up the beat from whatever Pink Floyd album you happen to be playing, and moves the laser patterns in sync with the music.