Guitar Hero: Smash Hits

Get Star Power, don't activate it.

Just strum until you fail, while you have Star Power available.

Pretty self explanatory. As others have said, get Star Power but don't activate it, and then just fail the song by rapidly over-strumming.

However, just a couple notes and suggestions:

Apparently it has to be done on medium difficulty or higher ... I attempted this on easy and I don't think you can fail a song on easy. At least, it wouldn't allow me to fail.

Also, for those of you who might have a similar problem to mine: if your guitar seems to always activate Star Power no matter how you hold your guitar (I have tried laying it flat and playing it like a steel-guitar, holding it upright and playing, holding it normal, reclining, every possible way ... keeping it still and it ALWAYS activates Star Power on its own), press the start button and go to options. Under the options, turn off (red x) the tilt sensor and you will not activate Star Power.