I wouldn't erase the files in your Band-in-a-Box/DragDrop folder, unless you are sure that your DAW isn't using them to play songs that you've made by dragging files to them. If you're using GarageBand, you're OK, and can delete files in that folder. But ProTools (depending on import options in ProTools) and Logic might expect the file to be there, and not have made a copy for itself.
1. GarageBand.
With GarageBand, this isn't an issue, as GarageBand doesn't use audio files from the Band-in-a-Box/DragDrop folder. GarageBand has made its own copy of the files, and saves them in the Project folder for the song.
So if you're using GarageBand, you can safely delete any files in the DragDrop folder, and not be concerned with this issue.
2. ProTools
If you have this option set in ProTools (Preferenes-Processing-Import "Automatically Copy Files In Import"
), then ProTools works like GarageBand above, and copies the files to its own folder, and you don't need to keep copies in the Band-in-a-Box/DragDrop folder, and can safely delete them.
If you don't have that option set, then ProTools will expect those files to stay in the DragDrop folder, as it will access them from there.
3. Logic Express
Logic Express just puts a pointer to the files, and doesn't move them automatically. You therefore cannot delete files from the DragDrop folder if you've dragged them. Note that inside the Logic Express folder, you can move the audio files from a Project (see 8:00 into the video referenced below for a discussion of that).
So, in summary, with regards to the issue of erasing the DragDrop folder inside Band-in-a-Box, if you've been drag dropping files to your DAW.
1. GarageBand users can safely delete the files, since GarageBand has made a copy inside the song's file on disk.
2. ProTools users need to be sure that the option (Preferenes-Processing-Import "Automatically Copy Files In Import") was on when they dragged them, and if it was they should have a copy of the files in their ProTools folder, and could then delete the files.
3. Logic and Logic Express users should not delete the files in the DragDrop folder, because it references them.
4. Other DAW users (e.g. Reaper) should assume that they shouldn't delete files in the DragDrop folder, until they see how their DAW handles import (ie if it makes a copy, or just expects the file to be there in the DragDrop folder always.
Note: If you take the extra step to Drag the file from the Band-in-a-Box green DROP button to the Finder - then the file will get copied to the Finder, and then you could safely delete from the DragDrop folder in the future.
So you could make a folder called "Files from Band-in-a-Box - do not delete" and then always drag your files to that folder, and then into your DAW.
We have a video showing how to DragDrop files to GarageBand, Logic Express and ProTools.
Go to this page
http://www.pgmusic.com/videos.bbmac.htmand click on the link "Exporting Band-in-a-Box songs into your DAW video on this page"