A 9-year-old girl is suing a centuries-old Berlin boys choir, arguing that her bid to join was only rejected because of her gender, in a case that has sparked debate over equal rights versus artistic freedom. The State and Cathedral Choir is one of the most renowned boys choirs in Germany, founded in 1465 by Fredrick II of Brandenburg. Over its 554 years, it has never admitted any girls. The girl, whose identity was not revealed to protect her privacy, auditioned with the choir in March and was rejected, according to the Berlin administrative court that is to rule on...