I am having nightmares at the even the remote PROSPECT of Gowan (or anyone else) singing Castle Walls or Queen of Spades.
There are many, many Tommy and JY songs from the Styx catalog, many listed here, that would keep people happy.
Man in the Wilderness, Young Man, Double Life, Love in the Midnight to name a few classic numbers.
And, of course, the songs from the "best album since Grand Illusion", Cyclorama. Surely they could include more of those. Ask Billy Bob along to tour.
They have a large number of fan friendly songs to choose from without using (and abusing) DDY penned/sung songs.
Bugsy