Guitar Hero: Smash Hits

If you have a full set of instruments, this achievement can be done without playing a single note.

Go to band career. Set all instruments to beginner, and let your fan play vocals. For the song, I picked Rock'n Roll All Nite (other songs may work, I didn't try). Now with the fan playing, even if you don't play a single note, you still won't fail. Just go through the song, and trigger star power on all your instruments whenever you have a full bar from the vocals playing.

As always, this achievement requires four players to have Star Power running at the same time. It does not need to be triggered simultaneously, all four players just need to be in Star Power at the same time, even if one player is just leaving Star Power.

The achievement will unlock at the conclusion of the song.

You can get this pretty easily on beginning alone. I played I Wanna Rock, as it has a ton of sections where there isn't much going on on guitar, and the drums are pretty easy, with a few alternations in it. Bass is fairly easy as well.

So basically what you do is strum guitar with your left hand, bass with your right, foot on the bass pedal for drums, and put the mic in front of a fan or other noisy object.

When you have enough star power for everyone to activate it, pause the game with the mic controller, set the guitars on the ground (like so in the video), un pause, then hit star power on the guitars with your feet, press A on the controller, and press X and Y on the drums, then voila!