So you're playing out somewhere, and you are up there doing your all. The light's in your eyes, you are sweating your ass off, playing your heart out. And you look in to the audience and no one is dancing. No one is even standing in front of you. What is going on? Is the audience a buncha weenies or what?
Having been married to a very good drummer who had as many paying blues and rock gigs in a week as he could schedule, plus his own art band, I can safely say I've been to thousands of gigs, listening on both sides of the stage--not left and right, but in front of the stage, talking and listening to the crowd and behind the drums/backstage listening to the band. So I'm an interested 3rd party. I want everyone to have a great time at shows.
First off, the audience may be a buncha weenies. It could be true. But if they are in a bar, listening to you, then they want to be a buncha weenies letting loose and having a good time. If they are standing far away from you, and not really dancing, it could be caused by many things:
1. It may be early and they may not be drunk enough yet. Not much you can do about that except remind them to get another beer.
2. The acoustics of the place may not be right for your normal volume level. If you are playing in a place with lots of brick and/or glass, the soundwaves are going to be reflected off the walls and hurting your audience's eardrums. You don't really want to hurt them, do you? They are paying for your performance, either directly through a cover, or indirectly by buying booze. Did you remind them to get another drink?
3.You may be blowing their minds. Honest. You may be so far out of their usual sounds and ideas, your audience may be struck dumb. It may be great to open their minds like that, but you probably want them dancing and acting all crazy anyway. The solution--your interpretation of a song everyone knows. I'm not asking you to do kareoke here. In fact, the exact opposite--when you show an audience YOUR interpretation of a tune, you are showing them who you are AND what they can expect from you at the same time. This isn't something you should do as a first song--or else the audience will think you are a cover band--but not the last either or it's a waste. Probably 3rd or 4th song in the first set.
Here's an example of how covers can be revealing, and exciting, starting with the original: