Add composer to pull down

I would like to use some standard names for composers. So it would be nice if the pull down for the composer tag contains the names of composers (which I would add to the pull down list) such that it starts filling composers from the list as I start typing (e.g. like Genre). I can only see and in the list currently. Is it possible for me to add composers and how do I do it?


see e.g. here:

Thank you @ohrenkino.