Analogy:
In The Impossible Game, its level editor allows you to choose your own song by simply pressing Ctrl + A or clicking the "Open Audio" button.
In osu!, you can simply drag any .mp4 file into the editor and you can start editing a beatmap (or set of beatmaps) for it.
Question:
Is it possible to do that in geometry-dash? (Store link)
The closest thing I've found to that is this:
Which basically restricts me to anything on newgrounds.com.
Can I use a custom-custom song (one not from Newgrounds)? If so, how?
Basically, any work-arounds?
Obviously on a map that I definitely plan on not uploading, but for my personal use.