That was an excellent suggestion shared by Jim Carroll about devices to keep the audiences interested in a long ballad. I would venture to say - the longer the ballad, the more skill necessary in order to keep the audience's attention, especially if it's unaccompanied. Certainly what this thread has brought out is that there are just so many ways to approach a ballad - and you won't be able to please everybody, so go with you gut about what's right for you, and what fits your interpretation of the song. If you love and respect the ballad, and work at it, you probably won't go too far wrong. Some basics should always be kept in mind - projection, diction, and not letting the instrumentation detract from the ballad itself. If it's there, it should be just for enhancement and shouldn't overwhelm the song.