Naturally, I made it play the dumb Witcher song, and also some tunes from Animal Crossing because… why not?
The first song is some lovely Town Hall music from Animal Crossing: Wild World, the next is one of the midday soundtracks from the same game (starting at 0:41 on the video above), and the one I know you’re really dying to hear is Toss A Coin To Your Witcher (skip ahead to 1:17). This musical magic is all thanks to a horde of invisible Symmetras that are programmed to play the tunes, thanks to a very cool Workshop tool created by Reddit user Wengzan. I don’t understand the exact science behind all this, but they’ve made a program that converts midi files into arrays that the game mode can read, allowing you to play a few minutes from pretty much any song as long as it’s in the midi format. It’s also set in a death match game mode, so you could invite in up to 12 players to battle it out to a tune of your choosing. You can try it out for yourself using the instructions on their GitHub page, though if you want to use specific songs like I’ve done here, you’ll have to find a way to convert them to midi files or find them somewhere online. For the Toss A Coin To Your Witcher tune I used Thomas Jonker’s handy midi collection, or for a bunch of old game music like the Animal Crossing themes, you can use sites like the Video Game Music Archive. However, if you don’t fancy faffing around with all the midi files yourself, Wengzan has a list of premade codes you can just pop into the workshop. Most of them are various battle themes from the old Pokémon games, and they make excellent background music for an Overwatch deathmatch.
There’s plenty more fun to be had in the Overwatch Workshop, too - you could play Tetris perhaps, do a turn-based 3v3 match, or maybe even turn D.Va into a spaceship.