That '90s Show/References

Cultural references
The title is a reference to That '70s Show, and the short lived That '80s Show.

"Weird Al" parodies Homer's song "Save Me" (Titled "Brain Freeze"), a parody of "Rape Me" by Nirvana, which harkens back to his actual parody of Nirvana's "Smells Like Teen Spirit".

Sadgasm's first song "Politically Incorrect" is a parody of two of Nirvana's songs combined "Heart Shaped Box" and "Frances Farmer Will Have Her Revenge On Seattle". The episode also made references to Sonic the Hedgehog, Zima, Seinfeld, Melrose Place, and Comic Book Guy mentions that The Lord of the Rings could never be filmed (although an animated film adaptation was produced in 1978). Homer mentions that Matt Groening was working hard on launching Futurama.

Homer's song "Margerine" is a parody of "Glycerine" by Bush.

The scene where "Marvin Cobain" calls his cousin Kurt to tell him about the new sound he's "been looking for" is a parody of the scene in Back to the Future where "Marvin Berry" makes a similar call to his cousin Chuck.

Trivia

 * This episode conflicts with other 'flashback' episodes. Past 'flashback' episodes feature Homer and Marge in their twenties/ early thirties during the eighties and early nineties and already had Bart, Lisa and even Maggie. This is due to the Floating timeline that prevents anyone in the Simpsons from aging with no suitable reason as to why.