If you can only have one lighting effect in your DJ arsenal, it should probably be a strobe light. The strobe light is a repetitive and bright flashing light that, when used in an otherwise dark room, creates the dizzying effect of life having a slower "frame rate." It creates a visceral experience for the audience, as opposed to just a visual one. When used at the correct times in your DJ set, a strobe light can add a whole lot of intensity and propulsion to the scene. Great times to use a strobe include when there is a significant rise in the intensity of the music (such as the addition of a strong bass line) or when the beat drops to create an ethereal mood.
Strobe lights are available for as little as $15, though higher-quality LED models will cost over $100. Super-wattage strobe lights and strobe packages can easily cost hundreds or even thousands of dollars.
Although mirrored balls, or "disco balls," often bring to mind unwanted memories of bad 70's pop, they continue to be a very popular form of DJ lighting. By simply shining a light on one of these rotating fixtures, you can create a very big effect for a rather small price; disco balls are available for around $50 to $70. Though some DJs will obviously shy away from disco balls, many recognize the nostalgic appeal of them and take advantage, adding a kitschy feel to their shows that many audiences will enjoy.
Colored LED light, such as moonflowers, strip lights, and derby lights, are also a staple of DJ lighting. The recent influx of LED technology means that DJs don't have to worry about overloading circuits and blown bulbs, and rest assured that their lights will last much longer than older DJ lighting fixtures.
Lights such as these project dynamic or static patterns onto the floor or walls of a venue. With the obligatory smoke machine, the shafts of light are also visible. These types of effects bridge a gap visually between the audience and the music. Even if there is an unexpected lull in your set, interesting lighting will keep the crowd feeling the beat.