A couple of other tips. If you have headphones such as Turtle Beach or Triton's, use them! You'll be able to hear the announcer better.
Also, it helped me to look away from the screen and focus on my controller. For whatever reason, looking at the screen screwed me up.
HOLD "LT" in during the entire game. Even though "Bop it" and "shout it" actions don't require you hold in "LT," it doesn't penalize you if you do.
Around action #58 the announcer will stop in the middle and say "ace" or "awesome" or something to that effect. Don't let it flub you up.
The achievement does not pop until the game is over. So once you're over 100 feel free to fail (I went to 150 and was freaking because I thought it glitched on me).
Feel free to add any comments or suggestions.