In the beginning there was not speech on one side music on the other. Social interaction must had been motivated by rythms to unite the tribe in a work.
Speech dont exist without body members gestures rythms and without throat/mouth motivated tonal sound (continuous vowel and discontinuous consonants) and specific body timbre.
In the beginning speech and music are one, and when they separate in the days activities they reunite in the calm of night.
Speech makes music through not only singing but speaking. And music spoke as in the Nigeria the Yoruba they call their drum "talking Drums". Yoruba is the name of a tribe of his language and of his drums.
Also music not only exist in time but exist as time itself, at least a time of his own.
Musical time is a specific musical concept...Musical time cannot be reduced to measurable physical time. It is a qualitative rythmic time linked to the body gestures felt as a rythm.
here from the web a few concepts about musical time you certainly know:
«Beat: The basic unit of time in music, providing a regular pulse.
Tempo: The speed of the music, often measured in beats per minute (BPM)
Meter: The grouping of beats into recurring patterns, indicated by time signatures.
Measure (or Bar): A segment of time corresponding to a specific number of beats, separated by bar lines
Time Signature: A notation that indicates the meter, specifying the number of beats per measure and the type of note that receives one beat.
Rhythm: The arrangement of sounds and silences in time, encompassing note durations, rests, and patterns»
Now these concepts come from written classical music.When i speak about musical time ( Ansermet wrote a huge book about it) i spoke mainly from the phenomenology of felt conscious qualitative time(a duration said Bergson debating with Einstein)
In our evolution it was the body improvising gestures that created his own time as a meaningful content to be repeated or commented by others body gestures as a musical and spoken answer in the tribe or in the social group.
I often wonder what the earliest music must have sounded like. I assume it had a strong beat and the melody from a flute or whatever was less important than it is today. Music is the only art that exists in time, as @mahgister has talked about, and I have a feeling that the beats in time are fundamental to any human music.