Warthur
What is the Grand Illusion? In the hands of Styx, it might be the boundary between full-blown progressive rock and radio-friendly AOR pop. The album finds Styx straddling that divide in a similar manner to the way Kansas would attempt from time to time - though whilst to my ears Kansas always got the best results when they stopped trying to balance the equation and just embraced their prog side, here I think Styx actually manage to master both the substance of AOR-pop and the texture and aesthetic of prog simultaneously.
With The Grand Finale recapitulating the theme of album opener The Grand Illusion, for instance, there's a certain sense of an overarching concept here, but as with Supertramp's Crime of the Century (another classic of the borderland between prog and pop) that may be more apparent than actual; either way, you get some really solid, hook-laden tunes here which manage to be smart enough to pique the curiosity of a prog audience whilst being straight-ahead enough not to abandon their pop roots. I think it's badly underappreciated.