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.
Magnum Opus - Generally considered to be the Live AlbumAt Fillmore East (also their commercial breakthrough), which is perhaps somewhat unusual.
Memetic Mutation - Before people shouted "Freebird!" as an in-joke at concerts, they shouted "Whipping Post!"
Legend had it that when a drunken concertgoer in Helsinki, Finland yelled for "Whipping Post" at a Frank Zappa concert, Zappa rehearsed and performed a rendition of the song mashed-up with "Montana", titled "Whipping Floss". The results can be found on You Can't Do That On Stage Anymore, Vol. 2. Zappa eventually did do proper covers of the song, which can be heard on Does Humor Belong in Music? (live) and Them or Us (studio).