I had the same questions. Defining the categories. Even intense is a bit hard to pin down.
I finally got around to reading this and ended up only skimming it (for now, anyway) because I've been swamped. I was a bit disappointed to see that the authors didn't provide a clear operational definition of the various music styles. This was as specific as they got (boldface added by me):
The factor loadings in the first data column of Table 1 show large loadings for electronica/dance, world, and new age, styles that are perceived as relaxing, unaggressive, and atmospheric, qualities consistent with the Mellow preference dimension. Genres with large loadings on the second factor were pop,
country, and religious, styles that typically have vocals and are perceived as uncomplicated, unaggressive, and simple, consistent with the Unpretentious dimension. The third factor included blues, jazz, bluegrass, folk, classical, opera, and gospel, styles that generally use acoustical instruments; are clear sounding; and are perceived as intelligent, deep, inspiring, and complex, consistent with the Sophisticated dimension. The fourth factor included rock, punk, alternative, and heavy metal, genres characterized by electric, loud, and distorted instruments, and perceived as aggressive, tense, and unromantic, consistent with the Intense dimension. And the fifth factor included rap, soul/R&B, funk, and reggae, styles that are percussive and electric and perceived as upbeat, danceable, and not sad, consistent with the Contemporary dimension.I kind of question the category labels because they very conveniently lend themselves to the acronym MUSIC.
A couple of other interesting things. My own experience and characteristics don't match up with this; for example, I love classical music, but I don't hold liberal values, and my artistic expression is basically nil:
For example, preferences for sophisticated musical styles (classical, opera, and jazz) are positively related to Openness, imagination, liberal values, artistic expression, and verbal ability. Preferences for intense music (heavy metal and punk) are positively related to Openness, sensation seeking, and impulsivity. Also, preferences for contemporary music (pop, rap, and dance) are positively associated with sociability, status orientation, and physical attractiveness. Openness is part of the five-factor model of personality (the others being Extraversion, Neuroticism, Agreeableness, and Conscientiousness), on which the research was based.
One other thing that doesn't fit with my own experience is the finding that degree of importance attributed to music declines with age. If anything, I attribute more importance to it now, if that's even possible.
Again, I'm so glad you flagged this Moogmodule. It was interesting.