However, in that case, "more musical" may differ depending upon one's musical tastes. If one was a thrash-metal fan, one might find different equipment "more musical" than if one was a fan of chamber music. If one was a fan of the latter, one might find a 12 wpc SET amp and some high efficiency speakers to be "more musical." If one bought that combination to jam out on Mega Death, one would probably be disappointed. A massive SS amp with some huge JBLs might be "more musical" in that application given your definition.
@immatthewj I see this as entirely false. The reason is that no-one has ever documented a way that electronics can favor one genre of music over another. As a result, what makes a system good at classical will also make it good at rock. As you know orchestras can play pretty loud. I play classical, gothic metal, electronia, folk music and the like all on the same systems in my house. They all do all forms equally well.
All humans share the human hearing rules. So we all very naturally concoct our musical compositions inside of those rules. So if you measure the energy spectrum of a well recorded metal band you'll find its not all that different from that of a well recorded orchestra at full tilt. I'm not saying that certain instruments are not asked to carry unusual energy for a bit; when that happens its usually not sustained unless the musician is making some sort of point. For example the piccolo in Mancini's Baby Elephant Walk.
When I encounter the myth that certain speakers or amps or combinations thereof can favor a certain kind of music, I've found that if I can dig into it, the simple reason for this is the person entertaining that myth hasn't heard everything- not every recording and not every system. The more exposure you have, the more light is cast upon this particular myth; the quicker it dissipates.