A more full explanation of the study is available here at United Academics Magazine. It's short and is worth a read.
The result of the study will surely piss off lots of people, especially rock and classical musicians, but it's fascinating nonetheless:
The rock musicians were the less sensible participants except from the non-musicians. This might come from the fact that they start quite late to practice their instruments and that they place more emphasis on style than on perfection. Classical musicians were most specialized in timbre processing. The use of “color” being one of their main means of expression. The jazz musicians were leading in pitch, location, intensity and rhythm processing. Jazz music is the most complex music genre regarding harmony and rhythm patterns. In addition to this, musicians have to communicate on a high level while improvising.