I agree with Willz, but I would add another dimension. Rather than just seeing where the cutoff (music vs. noise) is with various people, why not see if the cutoff is consistently different between groups of people? For example, do older people consider more things noise than younger people, or do men and women draw the line differently, or...?
One thing you might want to consider is how to choose your subjects. The more people you have take the test and the more varied they are, the more likely you are to get good results. If you just try to test you and an adult who's always complaining about 'that noise kids listen to these days', your sample will be biased and your results won't be as good.
Like Willz said, choosing the music/noise is going to be very difficult because it will be hard to get a continuum. One piece I think you might want to look at is Edgard Varese's 'Ionisation', which is considered to be a musical composition but is really just a bunch of noises strung together. You might also consider finding traditional Chinese or southeast Asian music--different cultures have different tastes when it comes to music; personally, I have trouble with anything that just has percussion (some traditional southeast Asian music) or has what I consider to be very jarring notes and disharmony (traditional Chinese music).
Anyway, let us know if you need more help!