Sophocleese - I hope you get over your nervousness about experimenting with high harmonies, there's no reason why we altos should have all the fun of singing harmony. I've just started singing duets with a soprano whose clear light voice just floats above my alto in amazing harmonies she writes herself, and it's a lot of fun for both of us to be experimenting (in my case, having to learn a melody and then stick with it!).

As for high notes being un-natural for me, it's a little of what MMario said (they feel forced, even when I can hit them) but it's also the texture of my voice and even my personality, I guess. My voice is earthy, my personality is earthy, and the low notes are just more "me".

Anyway, we need all kinds - that reminds me, I need to go learn "All God's Children Got a Place in the Choir" for a pet blessing next week....probably have to transpose it down a couple of keys ;-)