One of attributes of human language our writing systems barely reflect is tone. Roger Williams observed there was another layer to the indigenous languages he was attempting to capture in that there was not just sound but pitch involved. He never believed he captured all of it. Much of the intonation level information is thought be lost, extinct or reconstructed.
The parts of language that are not written phonetically tend to change rapidly between population groups, and that leads to many dialects. That is why modern Korean may have more in common with the ancient Chinese or Japanese pronunciation for words than do modern Chinese or Japanese equivalents. Korea adopted phonetic spelling first. An example in modern times would be Papa New Guinea with over 300 unwritten languages in use. The indigenous population of America before European invasion may have been three times the size. Extrapolating might suggest as many as 900 languages, and they may not have all used pitch the same way.
Little beyond punctuation and accent in English alphabet as written indicates pitch. If we want to control pitch we resort to musical notation. We think of music as different from language. The original human language is hard to find, and so the focus is on the languages that still are present. However, could it not be that the first language had more to do with pitch than phonetic sound?
What if our oldest language, the one never recorded as a language, was actually a set of pitches with meaning, like a song? Something like birds do. Song is very mathematical in nature, and can be very precise and carry over longer distances than pure speech. After all, we still use sounds and tone to communicate, along with sign language, when we do not have a common verbal language. Maybe there is a reason we are able to express our deepest emotion even today, in song. Maybe there is a reason some of us feel most worshipful in song.