@Adam – using “original” page numbers is the technique that a lot of ereaders (and epub) currently use, but it’s really not good enough. This “original” page number is meaningless in an electronic context, and differs according to platform, format – and what you mean by “original”. Page numbers are no longer meaningful or useful, and we have to break with this metaphor.

As for indexes and concordances – yes, this is something that editors (or even users) could build into electronic books in a more interesting and useful way than has ever been done before.

Imagine if you could import differently themed concordances into your book, by critics or professors, according to your own particular interests?

In my academic experience, I always loved the well-published editions, normally of canonical classics, that reproduced the original page numbers. My copy of Critique of Pure Reason was paradigmatic–not only did it reproduce the page numbers, but in sections of the text where the first and second editions deviated, the page numbers split off as well, labeled “A” and “B” for the different manuscripts. It was very intuitive. If a scanned book is converted to characters rather than simply an image (necessary for searching anyway, no?) it would seem fairly simple to embed the “original” page numbers to the text. Then one could search by this data, just as one does in class “original edition page 37, second paragraph…” I tend to think this sort of well-planned editing/publish effort is a better way of organizing the data, rather than creating a bunch of competing secondary app systems to search the data.

The difference to me seems to be with music, you are referring to a particular sound segment, which is difficult to describe (the one with the part with the ooh-aahs, and the bum-bum-ba-dum…) but in a text, the only thing one would want to direct to is text, which is pretty easy to search for already as text, without creating a new category of metadata. Page numbers, a standard for centuries, seems like all the data one might need.

Unless I’m misinterpreting or you see another context for reference?

Last thought–I love concordances–SO useful for research of prolific authors. Is there some sort of thematic concordance one could develop by embedding metadata that would be helpful? Like an index in the old school sense? A user-defined subjective electronic card catalog, complete with page and paragraph numbers? Is this more what you’re thinking about? Tags linked to text passages?