What does a lighter have to do with liking certain songs?
“I keep a lighter in my back pocket all the time. I'm not a smoker, I just really like certain songs.” - Demetri Martin
It's referred to the habit of the fans to light up a lighter when starts their preferred song...
Particularly, people would hold up lighters in the crowd during a concert. It's usually dark-ish at concerts if they're inside and the combined light is like a way of showing support/enthusiasm/whatever for a song being played.