During WW2, many German night fighters were fitted with a gun firing upwards,
to attack bombers.

Actually: 1. It could be one or *multiple* guns
2. They were at an oblique angle
3. It came about when some genius in the
Luftwaffe realized that RAF
bombers had *no* belly defenses;
[GEE! IF Churchill had asked NICELY; we COULD
have sold
him some B-17/24 type BALL
TURRETS OR THE PLANS
FOR SAME! ]

4. the Germans called then
"Schrage" (sic, needs unlauts!)
Musik" or "Jazz Music" in
German!