Comment 16 for bug 1899759

> Would this be an opportunity to move to the rekordbox format?

First, we need to merge the disjunct BeatMap/BeatGrid classes. I'm already working on that right now.

Then we can evaluate what the best storage format would be. I'm not sure that Rekordbox's storage format (documented here: https://djl-analysis.deepsymmetry.org/rekordbox-export-analysis/anlz.html#beat-grid) is really the best way to store such data. I personally find Serato's format (documented here: https://github.com/Holzhaus/serato-tags/blob/master/docs/serato_beatgrid.md#beatgrid-markers) simpler and easier to extend.

But first we need to refactor because the two classes duplicate all work that needs to be done.