Dear Maria,

I suppose the pastor/rector of the cathedral could make that decision, but of course the bishop would have the authority to override it and disallow the event.

I don't know the details of the singer or the concert, but from what you've told me I don't see anything appropriate at all of holding this event in a church.  I know sometimes we have secular classical organ recitals in our churches, but at least there is a practical reason to hold them there...  which is because that's where the organ is located.  Even so a lot of times people can use this music to lift their hearts to God, which is why this music is often used before and after weekend masses.

But for a modern secular singer I would think at least at first that a concert hall would be a much better place to hold the concert.

Mr. Slavek