Pennies from heaven is the same as a semi from the second
Common myth: if you drop a penny from the top of a skyscraper it would have the same velocity as a bullet from a gun and could kill a person. A penny thrown from a building will reach around 100mph
Pennies from Heaven is also a musical comedy from 1936 starring Bing Crosby which ties in with the later allusion to Singin' in the Rain.
There’s an old song called “Pennies from Heaven”, and one of it’s verses on the chorus ‘pennies from heaven’ is:
You’ll find your fortune falling all over town/
Be sure that your umbrella is upside down
Which is the setup for the following line.
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