Attaching existing server files to filefield How do you set an existing file path for a file field, in Drupal 7? The only option I see is to upload the file again.

In Drupal 6, FileField Sources seems to do this. 

Does FileField Paths or IMCE along with file field allow assignment of server files?
Is there an API to programmatically manage file fields?

Edit
I just discovered that this can all be done with the media module. I also have mediaelement installed. However it is not completely intuitive, so here are the steps I took:

Import to media library: /admin/content/media/import  

Create a mediafile asset field. This allows you to attach from the library.  

Display formats (example for audio) are at /admin/config/media/types/manage/audio/display/, instead of content type "manage display" which only provides "large", "small", "preview", etc.
I would try Media and its associated modules. It's an evolution of FileField Sources, and provides most of the same kind of functionality although with Drupal 7 fields.