For me, it continues to evolve as I listen to different equipment and learn more about what is possible (as well as what is not). I'm not a musician and don't have classical music in my blood, don't go to symphonies, etc. I have, however, always had recorded music I enjoy in the house and playing, and find that it can enhance almost any mood. Since most of the music I listen to is somewhat arbitrarily recorded (ie, rock/pop and all it's sub-genres), my reference is pretty much how the reproduction makes me feel. I'm not sure I want to recreate what an electric guitar "really" sounds like, or a kick drum, inside my house, though there is no doubt that as the system gets better, it recreates these instruments in progressively more exciting / involving ways. I went to the AC/DC concert the other night and paid attention to the fact that there really isn't a soundstage, and furthermore, the sound is pretty bright and edgy, definitely fatiguing (and no room treatment to boot!) - it was also fabulous, with a really great sound system, energetic instrumentation and vocals. In the end, the grading scale is how much the system / music makes me want to turn it on and listen.
What is your reference?
What is the reference by which you judge the sound of a component or a system? I see a lot of confused posts here, and listen to a lot of equipment at all price levels that sound phony, which leads me to believe that a lot of manufacturers and consumers don't really know what music sounds like. I am starting to wonder if many buyers of expensive equipment might actually prefer an artificial, hi-fi sound as opposed to something that approaches real music. I know that we are seeking a mere reproduction of the real event, so don't give me that babble about "nothing can duplicate..." That's a cop-out by those who can't hear or have given up trying. What is the aural image you have in mind when auditioning audio equipment? And what recording best represents that image?