Do we know what the deal is with uploading music? Can I upload music for just me or does my family have to share the 20k song limit? I'm not even sure which ver

Do we know what the deal is with uploading music? Can I upload music for just me or does my family have to share the 20k song limit? I'm not even sure which version of this I would prefer. I know between us we have more than 20k songs we'd upload, but we also could probably get by with being more selective about uploads because I've certainly uploaded some dupes.