Meaning
What does PepeJAM mean?
PepeJAM is an animated gif variant of the original Pepe the Frog emote, FeelsGoodMan.
The emote has headphones a hand and a moving motion added to FeelsGoodMan, to create one looking like he is jamming to music, that people can use to react to good tunes/music in the chat room of streamer on the website Twitch.tv.
PepeJAM is a variant of the many emotes created from the character Pepe the Frog:
Origin
What's the origin of PepeJAM?
The origin of the emote is unknown, but according to some articles on the internet, it was created as a sarcastic reaction to bad music, but the meaning has transformed into expressing enjoyment of electronic music played on the streaming website Twitch.tv.
A few different versions have been added to the browser extension FrankerFaceZ, which enables the use of unique emotes, but the earliest entry was submitted in April 2019.
Spread & Usage
How did PepeJAM spread?
Used as a daily driver emote on most streams on Twitch.tv, as of 10/12/2019. PepeJAM is 27th on the top 100 most used emotes list according to the website StreamElements.

External resources
- Know Your Meme โ PepeJAM