My system makes Billy Joel sound like Sir Georg Solti.
The goal is to make music sound as close as possible to what is recorded on the medium. Classical is often used as an example because it is easier to know what a piano sounds like than a rock guitar, as the latter is very dependent on the artist.
When my system was on display at THE Show last month, I got a lot of complements in the form of "the piano really sounds like a piano" or similar.