Can a great system make a mediocre recording sound good?

The best audio system is not revealing "per se" ...

Revealing of what?

Details?

A good audio system reveal the WHOLE through the parts and the PARTS through the whole...

Focusing on microdetails for their sake is the opposite of a good sound...It is fatiguing and not musical...

Many costly system in bad room sound like microscope...

I prefer my 500 bucks system in my audio room...

 ROOM Acoustic rule,  not details or sounds  plankton coming from gear ability to be a microscope for the ears...

I listen musicians not details...

I have to agree with mahgister. I want my system to illuminate the music it plays.. I want it to go for the gestalt.

To me, a great system is one that makes most recordings sound good and good recordings sound great. Too many audiophile systems sound good only when playing audiophile records. If you have a system like that, there's something wrong.

A lot of complexity in this question. In my mind there are 2 fundamental different ways to listening to music on a reproduction system: 1) you can listening to the musical idears ("Hey listen to that baseline. Listen how she waits a quarter note before she ends on the G") an 2) you a listening to The Illusion of the performance ("Now listening carefully how the the instrument behind the guitar moved back a little and suddenly separate! You hear it's a clarinet?")

Both ways of listening will improve when you upgrade, but only the latter is critical.

A rising tide lifts all boats.  A better system makes it sound better, but doesn't give the illusion of a well mastered recording.  And if played right after a well mastered one, the difference can be striking until your ear adjusts. 

Agree that the system should be geared to get the best out of music, and not to serve as a demo for audiophile recordings.