Schräge Musik

Schräge Musik (German pronunciation: [ˈʃʁɛːgə muˈziːk]) was a common name for the fitting of an upward-firing autocannon or machine gun, to an interceptor aircraft, such as a night fighter. The term was introduced by the Luftwaffe during World War II. "Schräge Musik" was previously a German colloquialism, meaning music that featured an unusual tuning and/or time signature (e.g., jazz). The standard usage of the adjective schräg is often translated as "slanting" or "oblique", but its slang usage is often translated as "weird" or "strange".

The first such systems were developed (though not widely employed) in World War I as anti-Zeppelin defenses by the French and British, in an era when fighters struggled to match the altitude capacity of the German airships and were forced to devise means to attack from below. The later resurrection of the concept by the Germans was inspired by observed weaknesses in the standard British night bomber aircraft of the WW2 era (the Avro Lancaster and Handley Page Halifax), which lacked ventral ball turrets in order to save weight, making them vulnerable to covert approaches and attacks from below under the cover of darkness. In keeping with the plans of the Allied Combined Bomber Offensive, the American B-17 Flying Fortress and B-24 Liberators operating in Europe (factory-equipped with ball turrets) typically bombed by day, thus experiencing far fewer encounters (and relative losses) from Schräge Musik. Later similar Japanese experiments with upward-firing cannons on their night fighters in 1944 (intended to target the American B-29 Superfortress fleet firebombing Japan by night) were largely fruitless, owing to the B-29's notably superior speed and altitude.

In the initial stages of its operational use by German air crews, from mid-1943 to early 1944, many attacks using Schräge Musik achieved complete surprise while destroying many British bombers. The crews that survived such attacks, during this period, often believed that damage and casualties had been caused by ground-based anti-aircraft artillery (AA or AAA), rather than fighters, and much confusion resulted until the cause was successfully pinpointed.

Background

World War I

During World War I, pusher-configured fighter aircraft with flexibly mounted forward-firing machine guns (especially the Royal Aircraft Factory F.E.2s), enabled gunners to discover the principle of zero-deflection shooting.