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.
Covered Up: Subverted in a rather odd way, "Electric Worry," is one half cover of Mississippi Fred Mcdowell's "Fred's Worried Blues" and one half original and while it is more likely for people to know about "Electric Worry" and not "Fred's Worried Blues," most people don't really pay attention to anything other than "bang bang bang, vamanos vamanos," thanks to Left 4 Dead, which is not part of "Fred's Worried Blues."
Genius Bonus: The lyrics often drop references to history, literature, myth and folklore that would only be clear to an enthusiast.
Signature Song: Averted for a while. Due to the aforementioned Left For Dead 2 commercial, it was Electric Worry. The band stopped playing the song after a few years. Then while on tour with Motorhead, Lemmy asked why they stopped and they said they were sick of it. Lemmy told them that it was a mistake, it was their "Ace of Spades." They resumed playing it after that.