“…language and music have a lot in common. They are both governed by a grammar, in which basic elements are organized hierarchically into sequences according to established rules. In language, words combine to form phrases, which join to form larger phrases, which in turn combine to make sentences. Similarly, in music, notes combine to form phrases, which connect to form larger phrases, and so on. Thus, to understand either language or music, listeners must infer the structures of the passages they hear, using rules they have assimilated through experience.
In addition, speech has a natural melody called prosody. Prosody encompasses overall pitch level and pitch range, pitch contour (the pattern of rises and falls in pitch), loudness variation, rhythm and tempo. Prosodic characteristics often reflect the speaker’s emotional state. When people are happy or excited, the frequently speak more rapidly, at higher pitches and in wider pitch ranges; when people are sad, they tend to talk more slowly, in a lower voice and with less pitch variation. Prosody also helps us to understand the flow and meaning of speech. Boundaries between phrases are generally marked by pauses, and the endings of phrases tend to be distinguished by lower pitches and slower speech. Moreover, important words are often spoken in higher pitches. Interestingly, some pitch and timing characteristics of spoken language also occur in music, which indicates that overlapping neural circuitries may be involved.”
Diana Deutsch’s Speech-to-Song Illusion.
Another idea about the origin of language is that it came from song. Ani Patel of The Neurosciences Institute in San Diego says this idea just feels right to a lot of people.
"We feel music just taps into this kind of pre-cognitive archaic part of ourselves," he says. So it seems to make sense that music came "before we had this complicated articulate language that we use to do abstract thinking."
Even Charles Darwin "talked about our ancestors singing love songs to each other before we could speak articulate language," Patel says.