Now by the time I get to verse 5, I am truly in over my head.

Having eaten, mine host feels like dancing, I get that much.
Dancing might be a euphemism for something else.
There is a rat's tail in the mix -- he literally catches a rat?
And then there are the "amorous pieces" -- yikes!
Are we talking lady-cats in heat?

Verse 6. At this point, it is only a matter of time
until the human, who thinks this is HIS house, wakes up.
Because now the singing starts.
Murner's father-in-law, named Hintz (don't know what that means),
lifts his voice in a pathetic plaintive noise.
And the first to join Hintz in song
are two run-down old tomcats
who are just as pathetic singers as he is
but they don't want to let him down
so they harmonize with him.

Verse 7. Every cat in the neighborhood is at the party now.
Everything they can do, they are doing, go down the list:
dance, blundering into things, raising a din until it crashes,
hiss, yowl, ... effervescence?? , clawing and scraping,
and NOW the landlord wakes up.