I'm much less qualified: I took a "World Music 101" class in college that described some Native American tribes whose songs had drums, and cries that fell in pi

I'm much less qualified: I took a "World Music 101" class in college that described some Native American tribes whose songs had drums, and cries that fell in pitch from high to low to call down the spirits from above, but their music had no concept of octaves. And I agree with you. While I can imagine a culture that hadn't "discovered" the octave, it's difficult to imagine people who can't even perceive octaves when presented with them, and quite easy to imagine other creatures that cannot perceive them.