Is it possible there's some odd harmonic series issue?
Not harmonic, it's non-harmonic.
The human voice is not a pure-pitch instrument. While the character of
musical instruments made by man tends to be dominated by harmonic
relationships, this is only partly true for the human voice. The voice is
what it is.
It appears that, in your case, there is a substantial component that is not
harmonically related to the fundamental, to the extent that it does not mesh
with the female's voice, which may consist more of harmonically related
components.
Bob Morein
(310) 237-6511
Sure. It may be that your voice just doesn't blend with hers. But
that isn't likely to happen on just one note. More likely, one of you
is not centering the note. Pitch correction can do a good job on a
clear, strong note that just happens to be the wrong one. But it
can't do much useful to a sour one.
Have you tracked once and made lots of attempts at pitch correction? I
suggest you practice the song a few more times and do some more takes.
Hopefully you won't NEED pitch correction.