honeydewgrrl, I agree about the Indigo Girls. I’ve just rediscovered my love for the self-titled album and Rites of Passage. The girl who asked me if I was the ‘harmony girl,’ later that night I sang “Ghost” with her and I forgot how much the harmony in that song gives me chills. I looooved it. Favorite song to add a third harmony to - “Love’s Recovery.”
KidCharlemagne, my friend J and I are like that, too, especially at the open mic nights. When someone else is up and singing, we’ll start doing the same harmony at the same time. We just can’t not do it.
AmericanMaid, maybe it is genetic. My older sister is an opera singer with perfect pitch, and she can certainly harmonize (I probably picked up the habit from her in the first place). OTOH, my mom sings also, but I think she said she can’t do harmony. Dad likes to sing, but he knows he never stays entirely in tune, so harmony is out of the question there…although he knows a good one when he hears it.
I’ve known singers/musicians who can’t read music, but I can only think of one who could harmonize easily. Hmm.