Washington National Cathedral is presenting free concerts this week evoking the history of great cathedrals from medieval times.



Thousands of chairs have been removed from the cathedral's nave to open up the space for the weeklong program.



On Thursday night, the Cathedra Choir will perform "Cosmography of the Spheres'' to evoke the tradition of liturgical drama. The concert will feature two dramatic works by Baroque composer Henry Purcell - "Dido and Aeneas'' and "Saul and the Witch of Endor.''



The tradition of drama in public worship dates back to the 10th century, when cathedrals were both houses of prayer and community centers.



On Monday, the choir performed music celebrating the life of Norwegian composer Knut Nystedt, in partnership with the Embassy of Norway.