How to add local music files to Spotify on Android

The first thing you'll need to do is add music to your Android device. This is the only step that can be a bit tricky. How I do this is to upload the MP3, MP4, or FLAC files to a Music folder (I created) in Google Drive. Then, using the Google Drive app on Android, I download those files to my phone. 

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There are plenty of other ways to do this, but this is the easiest way I've found. Of course, if you purchase music on your phone (from sites like Amazon), as long as the music files are in your Android Download folder (you can check this using the Files app), you're good to go.

Open the Spotify app and tap your profile photo in the upper left corner. From the slide-out sidebar, tap Settings and privacy.

In the Settings window, scroll down until you see the Local Files section. Tap the On/Off slider until it's in the On position. 

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You will then be prompted to allow Spotify access to music and audio on the device. Tap Allow to finish enabling the feature.

Now that you have your files on the device and local file support enabled on Spotify, go back to the main Spotify screen and tap Library. In the resulting screen, you should see the Local Files entry. Tap that and then tap play to listen to your locally stored files.