No, like this:
<Author>Chris Tomlin & Jesse Reeves</Author>
In EasySlides it is a single field where you can enter one or more names
As long as the tags are case-insensitive, I guess I could do a search and replace for:
"<Author>" to "<authors><author>"
"</Author>" to "</author></authors>"
and try again. I could then edit the fields in OpenLP where there is more than one author.