Playing music in bars is an interesting thing too. You're competing with drug energy, primarily alcohol. If you stay sober, you can see it, feel it, it's sort of like an electric haze that smears over the room.
It's not exactly as fulfilling as performing in a theater setting, but it has it's own special kick. I actually like playing in a room of totally drunk people, it's kind of like riding this strange, electric wave.
There's a sort of buzz, a danger, and you're basically fighting for attention. Not the best place for sensitive singer-songwriter stuff. Perfect for a more garage rock sonic assault.