Final answer:
The purpose of the special hall in Bayreuth is to perform stage works. It was constructed for the theatrical performances of a German composer named Richard Wagner.
Step-by-step explanation:
The purpose of the special hall in Bayreuth is 3) to perform stage works. The hall was constructed specifically for mounting the stage works of a German composer named Richard Wagner. It was designed to provide a space for theatrical performances, with features such as machinery for seamless scene changes, comfortable seating for the audience, and an orchestra pit to separate the musicians from the stage.