iD Software released the Quake source and as such there are a myriad of source ports that enhance the original release that allow you the ability to select a higher resolution and use mp3 or ogg rips of the original Nine Inch Nails soundtrack. On a side note, the Nine Inch Nails site says they...

Sweet! Thanks for the post! I'm not sure when I'll get to this, but at least I now know it's here.
Hey Jon! I can't remember which post was where we (me, you, and Travis) talked about Quake and the freebies. Well you can get all the games for 50% off at Fantatical. I just bought the Quake Pack. It has Steam keys. It's about $12.50. You can also get the individual games or pieces for 50% off, too. I think Travis said he owns these games anyway. I just thought I'd let the Cheerful Ghosts know. :)
Yep. I just picked up the doom original games steam pack for $7.
Not entirely sure why. I own them many other places.
HELP GREG I CANT STOP
LOL Well, I got the pack for $12.50. I paid with PayPal, but my bank still gave me a fraud detection error. I called the number and the automated system asked if I spent $12.50 to a games company in the UK, I pressed 1 for yes. The receipt I have even shows it's a UK company. Then it asked if I spent the same amount to the same company in CA and I pressed 2 for no. My receipts from Fanatical and PayPal don't show a duplicate charge, so I don't know what's going on. I gotta call the bank tomorrow to get it all straightened out, though I've already redeemed all the Steam keys and got them downloaded.
My email inbox is FULL of notices about games that are on my wishlist that are on sale. I have this for isthereanydeal.com and Razer software does it, too. I see more games that have significant discounts and I feel like getting them when they're really low, but at the same time I try to hold myself back so I don't spend too much money on games I may not yet be ready to play. I guess I've grown that infamous backlog everyone talks about. It's hard to resist, though, when a game is only a few dollars. LOL
2020. Huge backlog so many games so why not more!
I wanted to add some notes here about what I've noticed since I started playing this again yesterday w/ Quakespasm. I was able to get the music files into the id/music directory, but was still confused, because it seemed like they weren't playing. However, I have learned (since I didn't remember) that the music is for the most part a bit ambient. One track is almost just a bunch of whispering. There's a webpage you can visit that covers info about each map, including which track is played, you can find that here: https://www.quaddicted.com/quake/episodes_maps You may have to toggled the "external" music option in the options menu for it to work, but you can visit the maps and listen to the tracks listed on that webpage to verify that you're hearing the music. This confused me at first and apparently others as I did my web search regarding the issue I thought I was having. Since I found my solution, I thought I'd share it here.
To get Quakespasm to work, simply copy the files from the compressed file into the main Quake directory and overwrite what's there. If you want to access Quakespasm via the Steam default launcher then rename quakespasm.exe to Glquake.exe (or the other exe) and then you can select that option when loading up the game. Doing what I just stated, you'll want to select the GLQuake option. The game just looks for certain exe files, it only cares about what they're named, so if you change the name of a file to one that it's looking for then it will run that file.
If you want to cheat use the tilde "~" key and type in a cheat code like "god" or "noclip" without quotes. It's simple and easy and I'm sure other cheats are easy to find on the web. Be aware, though that if you use something like godmode, you'll have to reenter the cheat each time you visit a new map.
Maybe because I loved it so much when it came out, I still think it's a great and fun game.