display composer as artist only for genre=Classical

[adrian]

I have the setting

tagFormat=Artist.displayFormat={$composer^^: $artist}

which I wrote so that classical music would display the composer in the artist field. This works great, except that I have some pop music that came with the composer tag set. Usually I don't want to see the composer of pop music. One solution of course is to delete the tags from the files, but it seems a shame to throw away the information.

Is there any mechanism to display the composer only for files where there exists a genre tag "Classical"? I thought about trying to use the tagUpdate feature, but it seems not quite able to do the job (erase the Composer tag if there does not exist a genre tag set to "Classical"). Have I overlooked anything? (I could save the pop music composer tags in a custom tag, I suppose, and erase the main composer tags from those files.)