Some of us have been trying to sort songs into bins for a long time, Jon. If we don't it makes our study arenas far too wieldy. For instance some might say my 750-item database of 'Earliest versions' is far too small and restricted, but there were good reasons for making it that size and I can easily justify it. if I'd tried to include everything in the DT or Roud Index I'd be pushing up daisies before it got finished.