These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
"Grandad's Little Ditty" from Sailing the Seas of Cheese.
"Lermaninoff" from Primus and the Chocolate Factory, an entire five-second track where Larry LaLonde does a guitar cover of the Mozart excerpt that serves as Wonka's musical lock.
Ear Worm: Jerry was a race car driver, he drove so goddamn fast...
Epic Riff: Most famously, "Jerry Was a Race Car Driver" and "My Name is Mud." But also "Tommy the Cat", "Groundhog Day", "Hamburger Train", "Electric Uncle Sam" and "Lacquer Head." Most of them tend to be on the bass.
A lot of Primus and the Chocolate Factory qualifies for this if you're familiar with the original songs, but fittingly, "Semi-Wondrous Boat Ride" is a particularly triumphant example, being a cover of the film's most infamously scary scene. Well, there's that and the fact that Wonka's psychotic scream is replaced with Les giving an Evil Laugh.
The fact that the album closes with Les tearfully singing "Pure Imagination" while Larry's guitar part imitates a passing emergency siren doesn't help.