I am in charge of music for my cousins wedding reception, and they only want some light background music.?

You definitely want to stay away from the stuff if they're looking for light background music. LOL. However, it is always nice to try softer stuff like Phil Collins/Genesis, Eric Clapton, Peter Gabriel, Paul Simon, Sting/The Police, Frank Sinatra. Search Google for reception songs and you'll find some great stuff! Good luck!