What song is played on the organ during tours?

"A Mighty Fortress Is Our God," written by Martin Luther.

On our tour it played 'A Mighty Fortress is our God' but i think our guide says that it varies.

Mighty Fortess is Our God

A Mighty Fortress, although it can play other songs, this is what is played on the tours.

At present time the organ is playing “Amighty Fortress is our God.” Other selections on that may be regularly heard are “Shenandoah,” “Silent Night,” and “America the Beautiful.”

Mighty fortress is our God