Getting and Playing Local Device Songs On Spotify

This article is incomplete. Bug Aki to get it finished.

Summary

So your favorite song that you listen to ten times a day isn't available on Spotify, and now you are searching for a solution to your problem. You have found an article that will guide you in finding your music, getting it to your device, and adding it into a playlist upon Spotify. Each of these parts have alternate solutions. I'll try to point them out along the way.

Step 1: The Music

Many artist have their music available to purchase and download as MP3s. This is an excellent solution for your favorite song, as it supports the artist far more than listening to it on Spotify itself with a premium subscription. Bandcamp is a popular site for artist to sell their music on. Googlefu will be your friend in finding where, or perhaps if, your favorite artist has their beats available for purchase somewhere in an acceptable format. MP3 is a common standard that provides excellent quality within a reasonable data footprint, but other formats for probably valid. From this post, mp3, mp4, m4p, and FLAC are valid for playback. It notes that mp4 with video and m4a are not playable.

For demonstration purposes, if you don't have time to locate your favorite song, perhaps you would be interested in one of the following:
Hudson's Crimson
Wednesday's Wolves's Shake

Step 2: Getting the File Onto the Device

The best solution is to make the purchase from the device that you want to play the mp3 from. That way, when you hit download after your payment, it arrives to the download folder of the destination.

Step 3: Allowing Local File Playback

By default Spotify doesn't look at your local files for playable songs. This has to be enabled.

Android

In Spotify, get to a screen with your avatar in the top left of the app. For me, this is a big pink circle with a black A inside, as I haven't set my avatar in the app, and it picked a random color with the first letter of my username. Clicking this opens a menu. Go to Settings and privacy, then