I've discovered and tested ten ways to annoy/ruin the game of one playing Rock Band (or Guitar Hero, though results may vary).
Now, it may or may not change depending on what the person is playing, but it should work most of the time. But you can't be playing while doing this. So here are my ingenious ways of annoying the aforementioned player:
1. Turn off the screen. One of the simpler ways, usually done with a remote behind the couch. This is quite effective seeing as you have to watch the notes and words to play, and at very least hear it.
2. Put the t.v. on mute. You'd be surprised how hard it is to play instrument games with music.
3. Turn the volume up and down. The volume bar should cover up the upcoming notes.
4. Come into the room with a large stereo. Put in as loud as it needs to be to be as loud as Rock Band, then turn it on. The music is should be playing would be classical or rap.
5. Trip the singer and guitarist.
6. If they have never played before, tell them to go on Expert, and that Rock Band/Guitar Hero is actually really easy, and has skewed definitions of "easy."
7. Keep going, "Red, red, red, red, blue, red, red, red, blue, yellow, yellow, green, both at the same time!" right in their ear. Works quite effectively when you are saying the wrong colors, and when the player is colorblind.
8. If the player has his or her cell phone on him or her, keep calling and texting the person. If it gives you an option, say that it's an urgent call.
9. Keep trying to take their instruments away from them and saying, "No, you're not doing it right! Let me show you."
10. Simplest and most straight forward. Turn off the gaming system.
I hope this a) helps, or b) makes you on the look-out for the kinds of people who do this.
P.S. Ayah, if you're reading this, happy birthday!!!