Since I’ve been scanning large scores and aria/song anthologies to add to my digital sheet music library, I was curious as to whether it’s better to scan the whole book into a single PDF file, or break it up into multiple files that each contain one song. I posed the question to the forScore support team and here’s their response:
forScore was designed for one song per PDF, and the Bookmarks feature was added later as a way of accommodating larger songbooks. While the single large file with bookmarks is a perfectly viable option, you’ll probably have a better experience by splitting the PDF into smaller files. As far as the page turning goes, you shouldn’t see any difference between the two methods since it functions the same either way.
So, they claim that there’s no difference either way in terms of page turn speed. As for the “better experience” that you get from splitting the book into multiple PDF files, I’m not sure what they meant (and they didn’t send a clarification when I followed up with them about it)…
Technology for the Classical Singer 
My personal experience has been that I have had better luck with smaller PDF’s. Especially if you need to share them in any way. Besides, if you archive your music on your computer, then you are better off having the songs as separate files. IMHO.
I think I will do separate files for songs/arias, but one big file for the large-scale / multi-movement works. I realized while doing Messiah this year that it could be handy to put in links from the end of one movement to the beginning of the next one where I have an entrance, and as far as I know, there’s not a way to do that across two different files.
I’ve done both things…if I’m working on a large choral work with one of my choirs, I leave the whole score together and use Bookmarks for each movement. However, I do have some collections of materials and I’ve used Preview on the Mac to copy pages and to make a “New from Clipboard” file of just those pages.
You can also export a Bookmark on forScore as a new file. There seem to be resolution trade-offs when doing so.
I do love that you can turn bookmarks OFF in the main directory of files in forScore. When you are working on a musical theater production and you have thirty bookmarks, the directory can get a little cluttered.
Additionally: you can attach audio files, set tempos, and set pitches on a Bookmark, just like you can for an individual song.
Yes, I love how bookmarks have almost all of the features of a regular PDF file. I didn’t realize there was a resolution issue when exporting them, that’s good to know. I also didn’t know you could set the pitch pipe for a bookmark or file, thanks for the tip!
If I want to do one big file for the large-scale works, though, I need to figure out a better strategy for PDF file size/compression. Despite what the forScore folks said, my 50 MB Messiah score had SLOOOWW page turns and bookmark/slider bar jumps – it was barely tolerable. Steve R.’s PDF scanning workflow documented at https://techfortheclassicalsinger.wordpress.com/2012/11/29/a-choral-librarian-shares-his-workflow-for-scanning-and-distributing-electronic-sheet-music/ produces really slim files, but his process also sounds like a considerable investment of time and learning curve, so I’m on the fence about adopting it whole-hog. I will blog a bit more about my user experience with my Messiah score on the iPad later.