My friend and I both sing harmony as a duet. We agree that there are times when harmony should not be sung, even if the original artist may have had harmonies with the song. That is when the performer is singing it with so much feeling that you can hear their heart breaking, harmony only detracts from this instead of add to it. Also, like a privious post, if it is forced or off-key, nothing worse than the nails on the chalkboard effect when you are trying to enjoy something. Susu