Date last used info in song picker

Hi,
Currently the date info displayed in the Presenter song picker is date last edited. So both the visible date next to a song and the date sorting function are based on this last edited date. I'm sure this is useful for someone.
In our context, it would be more helpful to have date last used as the displayed date, and the sort-by date. In fact, I often forget that it's not the date last used, and wonder why we've not sung a song for so long, only the realise that we just haven't edited it for a long time!! Thanks!