the thing about sweetening (at least in the 60's/70's sense) was that you really couldn't perceive the strings and horns as such...they were placed so faintly in the mix that what they added was a certain undefinable/undeniable presence...(in fact, LP's used to only credit the sweetening arranger, not the actual musicians involved)...hence the warmth of sound that was so appealing back in those days...