Musical light control boxes can synchronize the dimming and illuminating of light bulbs, keeping time with the music as the music plays. Some musical light control boxes can sync lights with internal music. Other varieties allow users to play their own music through the boxes, using a "Line In" audio connection. If a hard connection to your musical light control box isn't viable for your setup, you can synchronize your music and light via radio frequency.
Things You'll Need
Light control box (with "audio in" port)
Wireless FM transmitter
Plug your Christmas lights into the power outlet on the light control box. Plug the light control box's power cord into a wall outlet. Switch on the light control box's power switch.
Plug an FM transmitter's 1/8-inch audio connector into the "Audio In" port on the light control box. Switch on the FM transmitter's power switch (see Tips).
Set the FM transmitter's frequency with the radio frequency you wish to use (see Tips). Match the radio's FM frequency with the FM transmitter's frequency.
For light control boxes that feature both an "Audio In" port and built-in Christmas music, you will have to set the control box to receive "Audio In" music. Toggle the light control box's "Audio Selection" or "Music Source" switch to the "Audio In" setting.
The procedure for selecting a frequency will vary, depending on the brand and form factor of the FM transmitter you use. Some FM transmitters will require you to select a frequency using a slide button, while others will require you to select a frequency from the FM transmitter's display.