I have tracks saved offline in Spotify. I also have individual MP3 audio tracks that I have manually added to my music folder in my phone (Galaxy S6). However, if I want to shuffle everything then I have to jump between Music app and Spotify app manually. Which is a pain, and a bit dangerous if I'm driving.
What I'd like to do is be able to 'merge' all these tracks together. Whether this is a single playlist of everything, or a way of moving my local music into Spotify app, something like that.
One option i had was to just re-download the local tracks in Spotify itself, but not all the music I have is found there.
How can I merge all my music from my device into one usable playlist?