I have found over the years that a great test of a hi fi system is music that combines four things: full bodied vocals ( solo & harmonies), acoustic stringed instruments ( like acoustic guitar, banjo, mandolin, violin, stand up bass etc), amplified instruments like guitar, bass guitar , keyboards) & drums. Not many systems can do this well at realistic volumes in a decent sized room especially when these sound components are all playing together. These very varied sounds & dynamic shadings often tend to get pushed together & loose their inner detail & nuance.
A perfect example of this are the first two Jackson Browne albums which both sound very good on Qobuz if a good album copy is not available.