Underglow kit says it flashes with music? Don't understand how this works?

I just installed my underglow kit and it said that it is supposed to flash with the music. There is an on/off button, all bright, and change button on my main control. My neon lights don't work when the all bright button is not pushed down. I don't understand what is going on here? Any help would be helpful! Thanks!Underglow kit says it flashes with music? Don't understand how this works?
Usually there's an ON-OFF-MUSIC switch, which gives you the option to have it on, off, or flash when it feels vibrations, specifically music.