I actually listen to a wide variety of music, anything short of true hip hop, reggae and hardcore nu-metal. Picking test music is troublesome or me.
It can be quite an interesting morning for the dealers when I visit, one min i'm listening to Freya Ridings and London Grammer then swing to listening to death from above 1979, Nothing but thieves and korn (old school korn).
With many other artists thrown in for good measure with some of my favs lately being Lilly Moore, Robert Glasper (covered being the album i like), fieh, Portico Quartet, Clare-Maguire and many more.
Speakers to me have to play everything well, and dynamics are the single most important thing to me I've found, sacrificing a little bass to do, so be it. Hence my chosen speakers Klipsch heresy 3's
I don't believe you have to intermit knowledge of music to use it as a test, You know a good sounding album when you hear it. But that same music needs to be used across all the speakers during that audition. Listening to one type of music through an audition is a little silly to me.
For instance, I liked the brand Russel K and the speakers sound lovely and they really do deliver on bass and mid-range and have lovely sweet treble. Fine for the most part but certain music will bring unwanted characteristics. So while listening to Korn freak on a leash brought out some unwanted port turbulence that didn't show its self while listening to less demanding music, and this happened at any volume. Switching gears to something that really pushes bass response Dj shadow three ralphs, rendered that track unlistenable through the Russel k.
Now i would have never of found that out if I was just listening to acoustic singers and in this day and age port noise just shouldn't exist.
BUT I also go out of my way to listen to badly recorded music, music with mistakes not just quite sounding albums but albums with loose bass and strange phase issues and the sort. to see how the speakers handle this sort of thing.
Just my thoughts