We had these a long time ago; 'module files' made with music trackers [1]. And yes, they compress very well.
Unfortunately, the transformations that make up 'mastering' can be pretty elaborate, and for professionally-produced music there is little incentive to let the general public see their project files -- although they are occasionally made available for remixers.
Unfortunately, the transformations that make up 'mastering' can be pretty elaborate, and for professionally-produced music there is little incentive to let the general public see their project files -- although they are occasionally made available for remixers.
[1] https://en.wikipedia.org/wiki/Module_file