How do you handle it?
Piano man, American Pie, Rappers Delight.....you just sang 25 minutes of the 4 hours.
There is one song longer than AP and I can't think of it now. Then you have Paradice BTDBL and I'm sure there are more.
If the rotation wasn't too long one sly singer could actually do a 1 hour solo show

Would you let them? Do you think the othe singers would complain?