9 Infamous Movie Plot-Holes (Solved By Fans)
4. How Was Marty Playing A Guitar That Hadn't Been Invented Yet? - Back To The Future
The Plot Hole
At the Enchantment Under the Sea dance, how is Marty (Michael J. Fox) able to play a Gibson ES-345, which wasn't produced until 1959, some four years later?
The Solution
Redditor iSphincter solved this one in a manner that's both hilariously creative and creatively water-tight - beyond the obvious fact that somebody in the prop department clearly messed up.
They argue that Chuck Berry's cousin Marvin Berry (Harry Waters Jr.) and his band the Starlighters were themselves time travellers who helped Marty ensure his own existence in order to maintain the continuity of the universe. Yup.
This explains why Marvin has a guitar that doesn't exist yet, as well as why we can hear a reverb tank when Marty kicks over the amplifier, which itself wasn't invented until 1961.
Accepting that the guitar was vital in making Marty's parents fall for one another, and that the Starlighters managed to keep up with Marty's rendition of "Johnny B. Goode" despite apparently never hearing the song before - it also not existing at the time - it's incredibly easy to believe that they too were time travellers.
That's without mentioning the profound "luck" of the band sitting in the very car that Marty is locked in, eventually allowing him to escape.
Marvin then fakes cutting his hand in order to get Marty on stage to perform his barnstorming rendition of Johnny B. Goode, get his parents together, and ensure the universe unfolds as it should.
Though this is unlikely to ever be formally confirmed by Robert Zemeckis or Bob Gale, it totally works without disrupting the series' delicate approach to causality.