Cannon sounds have sometimes been used in classical pieces with a military theme. One of the best known examples of such a piece is Pyotr Ilyich Tchaikovsky's "1812 Overture". The overture is to be performed using an artillery section together with the orchestra, resulting in noise levels high enough that musicians are required to wear ear protection. The cannon fire simulates Russian artillery bombardments of the Battle of Borodino, a critical battle in Napoleon's invasion of Russia, whose defeat the piece celebrates. When the overture was first performed, the cannon were fired by an electric current triggered by the conductor. However, the overture was not recorded with real cannon fire until Mercury Records and conductor Antal Doráti's 1958 recording of the Minnesota Orchestra. Cannon fire is also frequently used annually in presentations of the "1812" on the American Independence Day, a tradition started by Arthur Fiedler of the Boston Pops in 1974.