This can be earned along side "Rock the House" and "Prime Time". It requires you to score over 10,000 points in one go as a DJ and will be the hardest achievement to get.
What I did was alternate one arm up one arm down for the dance motion. Make sure to keep with the beat.
What I felt was most important was the voice prompts to pump up the crowd. When the mic was blue I said "Everyday I'm shufflin". Start saying it as soon as you skip the cut scene as well as the dance motion. When the mic is in "cooldown" wait for it to almost fill then start saying it a little in advance to get the points a fast as possible. Redfoo from LMFAO tells you things to say, this one worked for me.
As far as the DJ motions I just kept moving my arms in the same up and down motion for the prompt that has the up arrow. The other one is simply a sweeping type motion from right to left. I did not even hit all the DJ prompts and still got it, but barely.
What I found that worked was stand with your arms up at 90 degrees. Next you just continue slightly swinging them forward and back, to make it count as fist pumps. Whenever the voice icon come up just say, "Make some noise!" You can actually start saying it just before it fills to get it quickly. The only part I really had trouble with was the side swipe movement, got everything but one and only passed 10,000 by a measly 20.
Just keep working at it and you should be able to get it.
Your scoring doesn't start over for each section, but accumulates through the 3 chapters (fight, dj, red carpet). If you got a perfect on the fight scene, that's 4000 points. That means in order to get this achievement, by the time you do your stage dive, you will need at least 14,000 points in order to unlock this achievement.