I have had experience in teaching music to young children. I agree that to a baby, speech is music. They are fascinated with the tone, inflection, and how the sound is produced. Babies will look intently at a person’s eyes and mouth when they are being spoken to even when they haven’t a clue what is being said.
They love being read to even when only a few months old. Story telling with exaggerated vocal inflections is music to them.
Speech is tone and rhythm in a usually narrow range of pitch and with short tones, rather than long ones.
I wonder how this relates to dogs and dog training? A lot of dog trainers use elaborate vocalizations and tones to train their charges. "G-o-o-o-d B-oi-oi-y" And some use only hand signals.
The third word I learned was “Usmic.” Mom would put on a stack of piano Boogie Woogie 78s to keep me entertained and quiet. When the stack played out, I’d start screaming for “Usmic! Usmic!” and she’d flip the stack over. Explains a lot! I hear music in my head, non-stop.