An artist's release date - multiple albums in a year

[ohrenkino]

I do not think that this is an MP3tag problem but a player problem.
In general, the field YEAR is defined to be a 4-digit-field by the ID3 standard. So there is not real space to expand it.
The more accurate date would be RELEASETIME which allows you to define the date down to a second. The question would be whether your player can cope with it.
I wonder whether your player really only considers the year ... and if so .. you could trick the player and add an non-suspicious character to the album artist's name for all the additional albums in a year like "Beatles" become "Beatles_". The player should treat the Beatles with an underscore as a new artist.
If you are not satisfied with the current player, see

Android Media Players

There are many players on the Android platform, but almost all use the base Android APIs and media library that limits their functionality and performance that don’t make them much different than the stock player other than cosmetically. One player app that breaks from this trend and I have been using for some time is GoneMAD. It builds its’ own database library, and key to me is that it supports the use of sort tags for Album, Artist, AlbumArtist, and Composer. It also supports multi artist an…