When I'm recording I like to dim the lights, switch on the old lava lamp, and let the mood permeate the music.
I have amber lights in the table lamps nearest my keyboard, and it really adds warmth to the room.
There would be very few situations where I wouldn't use some kind of lighting.
One of the bands I played in had a projector that shone against the wall behind the stage and it had gel slides that heated up and made all kinds of crazy images.
Ian
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.