What opera company has its permanent home as he Staatsoper Unter den Linden and had Franz Betz as an opera singer in the 1800's?
Franz Betz: Franz Betz (19 March 1835 – 11 August 1900) was a German bass-baritone opera singer who sang at the Berlin State Opera from 1859 to 1897. Berlin State Opera:  Its permanent home is the Staatsoper Unter den Linden, commonly referred to as "Lindenoper", in the central Mitte district, which also hosts the Staatskapelle Berlin orchestra.
i don't know