Someone modded their Switch Joy-Cons to play the classic Super Mario Bros. theme song using the rumble feature, and the resulting tune is incredible. Better yet, the program they used is publicly available and uses MIDI files, so it should be easy enough to turn your own Joy-Cons into little rumbly music boxes.
Redditor Sarossilli's program Musical Joy-Cons (opens in new tab) adjusts the Joy-Con's rumble frequency to mimic the melodies from imported MIDI files. Want your Joy-Cons to lull you into a relaxing sleep with The Forest Theme from A Link to the Past? How about a vibrational mix of Donkey Kong Country 3's Rockface Rumble for your next HIIT workout? Musical Joy-Cons gets it done.
If you are exceptionally bored and want to run this program on your Joy-Cons, Sarossilli provided instructions (opens in new tab) on how to do so. There's a ZIP file you'll need to download and extract, but from there you just need to connect your Joy-Cons to your PC using Bluetooth (which is surprisingly easy), and then after a couple more simple steps, you're all squared away.
Just keep in mind that Sarossilli says the Windows version is "really early and buggy" and that there are some limitations (opens in new tab) as to the notes the rumble pack can accurately hit, so it's best to temper your expectations for now. For reference, here's Megalovania from Undertale, which sounds great, and a rough cut of the Doom theme that doesn't sound so great (though an improved version is in the works).
While we're on the topic of video game music, here's a list we put together of the 25 best gaming soundtracks of all time.