Assuming there is a general agreement that genres should not change much or at all within a release group.

Based on discussion here:
https://community.metabrainz.org/t/suggestion-combine-and-synchronise-genre-tags-between-all-releases/531271

"While I can understand that ‘other tags’ probably should be unique for a release vs. shared over the whole release group, I see no good reasons why the genre tag should be.

Currently you can have it that the exact same album will show ‘soul’ for one release, ‘blues’ for a second, ‘jazz’ for a third, and no genre tag at all for the others.
That doesn’t make much sense to me, and it isn’t useful.

My proposal is that the validated genre tags get shared and synchronised between the release group and all it’s containing releases, and that they all get displayed on both the release page and the release group page."

There shouldn't be much change to the UI needed. It might be simplest to tally tags that are on the genre whitelist in all the releases and the release group, and then display the result across all those pages instead of what it does currently. A question is if it is possible (or necessary) to remove duplicate votes for a tag by the same user in the final display.

Potentially add a symbol next to 'genre' in the sidebar that you can rollover displaying something like: "collates genre tags/votes from across the release group"
To prevent confusion.

Picard would need changes to pull the collated list instead of the individual ones for tagging.