The musician put together a band that included blink-182 drummer Travis Barker to perform the show live from his house in Salt Lake City, Utah.
Alongside Barker and Malone, Nick Mack played the guitar and Brian Lee completed the line-up on the bass guitar.
The star donated the money raised, which totalled $2.8m (£2.26m), to the World Health Organisation and – Malone said – it will “ensure patients get the care they need, front line workers get essential supplies, and accelerate efforts to develop vaccines, tests and treatments.”
He also added: “Thank you to the gentlemen who wrote these beautiful songs.”
Then he launched into ‘Frances Farmer Will Have Her Revenge on Seattle’.
Over the course of longer than an hour, he also performed such Nirvana classics as ‘Heart Shaped Box’, ‘Come As You Are’ and ‘About A Girl’.
They seem to have struck the right chord with frontman Kurt Cobain’s wife, the Hole singer Courtney Love.
Love was moved to congratulate the band for their efforts to raise the money, and wrote: “GOOSEBUMPS! F*** YES. Go have a margarita @postmalone. Nothing but love from here. Congratulations.”
Before the show, she had tweeted: “Thank you mighty kc for writing these songs with your elegant and monkeyed hands that the kids still want to sing and play and hear and use to fight and hunt and cure and heal and eradicate this f***ing covid19 virus. I approve the usage. Good luck mr malone.”
Former Nirvana bassist Novoselic also said: “I don’t think these fellows can play any better. They are on fire!!!!”
He added: “Hello!!!!!! I love you all!!!! I am holding emotions back the whole show.”
If you want to watch the show, it’s available in full on YouTube right now, and you could even go and drop a few quid their way if you are so inclined.
All of the donations will be given to the United Nations Foundation’s Covid-19 Solidarity Response Fund for the World Health Organisation.
On top of that, all of the money that is raised will be matched at a rate of 2:1 by Google, up to a total of $5m, so the more people pay in, the more Google will donate too.