Who else uses music and lighting during their games, I've used everything from Rainbow (the "Rainbow Rising" Album) to Movie soundtracks for the music; and Oil Lamps to Candles for the lighting.
I had an interesting experience while back, and it involved music.
The scenario was a fairly simple city based adventure, involving a kidnapped nobles daughter and a death cult dedicated to Orcus.
I had played some Monks Plainsong as background noise during the chase through the temple and into the sewers.
The next section of the scenario involved them exploring caves under the city, and rather than turning off the cd player as I had thought - I had turned it right down instead.
The Plainsong CD was playing, almost inaudibly - and that combined with the lighting (which was candle-light at the time - I find it evocative during spooky scenarios) really started to agitate the players. The were becoming more and more twitchy and nervous as the explored the caves.
All I can attest it to was the music - though they couldn't hear it consciously I think it was was affecting them on some subconscious level and combined with the lighting and the mood of the scenario was "stressing them out".
When we finished the session, they all commented how scared they were feeling and said it was the most fun they have had in ages - better than a scary movie!
SO if you really want to create some atmosphere during games, don't forget the Music and the Candles!