Heads up! This list contains a spoiler if you haven't finished season 4!
Finn Wolfhard, aka Mike Wheeler from Stranger Things, when viral in 2017 for his former band's ('Calpurnia') cover of "My Kind of Woman" by Mac DeMarco.
Finn Wolfhard now makes music in the band/duo, 'The Aubreys'.
Joe Keery, aka Steve Harrington, released music in his early 20's under the name 'Cool Cool Cool'.
However, it is more widely known that Joe belonged to the band 'Post Animal' up until 2019, where he performed drums and guitar.
Joe Keery's current music project is 'Djo', and is set to play Lollapalooza this summer!
Caleb McLaughlin, aka Lucas Sinclair, currently releases solo music!
Maya Hawke, aka Robin Buckley, released her debut studio album in 2020 and is currently on tour!
Gaten Matarazzo, aka Dustin Henderson, played in 'Work In Progress', a 7-piece band that fizzled out in 2019, but not before touring and performing in festivals.
Jamie Bower, aka 001 or the orderly, started out with a solo project using his full name, Jamie Campbell Bower.
Afterwards, he belonged to the band 'Counterfeit' until their split in 2020.
Now, Jamie Bower is releasing solo music again - without his middle name.
Charlie Heaton, aka Jonathan Byers, used to drum before his Stranger Things days!
Dacre Montgomery, aka Billy Hargrove, has a non-traditional approach to his space in music. He writes rhythmic poetry and collaborates with musicians to set them to music!
Honorable mention: Millie Bobby Brown, aka Eleven. While Millie doesn't have any original music, that hasn't stopped her from showcasing her voice.