Quarter centuries index for classical music?

[simbun]

If you want simple, just generate the tagUpdate script from 1600 to 2100 (as @stefano_mbp seeemed to be suggesting) and you'll never have to consider it again :-)

As I said, if you generate the tagUpdate script it'll give you the chance to play around with both options (quarter or half century) before settling on one or the other (or both). There's nothing worse than spending hours/days making a change only to realise that it's not quite what you wanted/needed.