someone said before, If they pay to go to a John Prine concert,
they sure as heck hope he will monopolize the stage. That is what people came to see and hear and PAID for.   I would be pretty upset if I paid good money and ended up seeing the stage shared by someone else for half the concert ...

It is their concert, pay and go see them or don't pay and don't see them. The beauty of freedom is we have the choice on how to spend our money and what entertainment we choose to spend it on ... right