To search for songs sharing a tune:
First look up a song in the blue search box, ie limerick
look at the bottom of the file for tunefile: In this case LIMERPRG
put this tune filename in the search box. this shows 7 hits.
you may not get everything if we used a different tunefile name on some - say we entered a tune, listened to it and said "Oh that is such and such" after we entered it.