1st 2nd and 3rd are out of focus, and I don't think they quite capture what you're going for. You needed a more creative angle - next time try shooting low, from about his 11-o'clock through his hands to see his face behind with the turntable looming in the foreground. Also on the 1st you have your subject dead in the center - - not as appealing as your 3rd where you have him on the left 1/3rd vertical. The 4th is the best of these series. It could use a little less exposure - I suspect you had the cam on auto-exposure and it was factoring in all the darkness in its iris equation.
The 5th is a good silhouette, but if you'd moved about a step and a half to the left it would have been better - he'd have been silhouetted against the light background instead of the darkness.
The 6th is the best as far as emotion - the guy's actually smiling. Unfortunately the framing is off - - -If you wanted to show the screen you should have moved more in front of him. As it is now, you have the horror-movie framing - - -any time the pretty girl in the horror flick is about to be killed, they frame her on the right side of the screen, facing right, so you can see the emptiness behind her that's about to be filled with the monster. Otherwise, if they're facing right, they should be on the left, and vice versa.
the 7th is good! Love the motion blur on the hands.
the 8th could be a lot better - the motion blur of him moving his head is great, but unfortunately your camera isn't steady and so things that aren't supposed to move - the equipment - are blurred as well. Destroys the effect. Picture crisp, sharp, glowing audio equipment with that fast movement from the artist - - you'd have one hell of a motion shot. You need to go get a tripod.
The 9th just needs some recomposition - you should have stood so that the column almost blocks the view of the guy at the turntable - put that in the foreground, and then you'd have some real depth to your pic, while also compressing the interesting stuff so there isn't a big black hole between them.
The 10th, with the green laser, is your best shot. You're a little overexposed in the center, but then with all the flashing lights it's nearly impossible not to be. The color mix, fromthe purple walls to the green lasers, to the sprinklings of blue off the disco ball - all REALLY nice. About the only thing I might do is to frame it so less of the ceiling shows - - the light poles and insulation detract from the really nice almost mystical look you have going.
For the same reason the 10th works, the 11th doesn't. It's a confusing collection of light blobs with a few green lines going through it. Could have worked better if you'd set the camera on a tripod, irised WAY down, and set it for a 30 second exposure to let the laser go crazy and a lot of motion to happen on the floor.
too much headroom on the 12th, and the focal point is the plywood box. You needed to move around to his front again to get his face to be the highlighted area.
The 13th is crazy, and I really like it. That's art.
the 14th is also art - we have no idea what the hell the scene is, but it's great abstract art.
Other tricks to try with an SLR on a longer exposure is to zoom the lens in or out while the shutter's open. This takes a VERY steady hand, but if you do it right, the subject in the center is in focus and whatever surrounds it gets these wild streaks going.
Like this (no I didn't take it)
Using this effect in a club setting could yield some really crazy shots, especially with that laser going.