Depending on your instrument of choice their will be performance guidelines at every level of NCEA. Below are a few guidelines you can work from. Rockschool are excellent guidelines as well.
You simply select your instrument, then go to Grade 4 & 5+ which is NCEA Level 3 and look as the Technical Skills, and it also has Performance Pieces, if you get stuck on trying to find an appropriate song to play.
NCEA Level 1, 2 & 3
NCEA Level 1, 2 &3
NCEA Level 1, 2 & 3
NCEA Level 1, 2 & 3
NCEA Level 1, 2 & 3
NCEA Level 1