I am trying to set up my app so that it will accept audio files dropped on to the application icon. I'm stuck at the first step - specifying the document types that I want to accept in my Info.plist. As I understand it, I can use the UTI "public.audio" to avoid having to enumerate every single supported audio format. (I'm not concerned about backwards compatibility.) To this end, I've set up a document type in Xcode's target info window, like this: Xcode has added the following to my Info.plist file: Code: <key>CFBundleDocumentTypes</key> <array> <dict> <key>CFBundleTypeName</key> <string>Audio</string> <key>CFBundleTypeRole</key> <string>Viewer</string> <key>LSItemContentTypes</key> <array> <string>public.audio</string> </array> <key>LSTypeIsPackage</key> <false/> <key>NSPersistentStoreTypeKey</key> <string>Binary</string> </dict> </array> Unfortunately this doesn't seem to work. I can't get my application to "darken" when I drag an audio file onto it. I have tried cleaning the project and rebuilding, but that doesn't help. I'm sure I'm missing something very simple, but I have no idea what. Apple's documentation on the subject isn't very helpful - the UTI documentation is quite sparse, and the documentation for setting up document types doesn't show how to use UTIs.