Yeah, but if Poweramp and many other players and tag editors recognize multiple values when using "; " as a separator (which is a standard), why can't MB write those values that way?
Why should it have to use multiple fields? It's the only player I know that write multiple values into separate fields. And of course MB can handle those values correctly because it's the one that writes them that way. Now the point is MB can handle multiple values well, also when they are written in a single field and separated with "; " (the standard method).
So the solution is very simple: Make MB write multiple values into a single field each separated with "; ", just like it is shown in the tag editor, just like many other players and editors do.
PS: Poweramp handles multiple values well when using the standard characters like "; ". It seems it is not optimized to detect/display multiple fields of genres correctly, since it is a very rare case (only people who use MB to tag their music will face this issue). But Poweramp complies with the standards.
PS2: This multiple fields thing is the one that causes GoneMad to show genre like this: "R&B Soul". If you retag that file with Picard or foobar2000, GoneMad will show "R&B; Soul" which makes more sense than the previous.
Thanks for the reply!