I dont want to contradict the great Sibelius...
But music begun when the body gesture called speech begun.
Speech is a rythmic social coordination and timing of attention through body gestures , it is music...Speech and music are born together like siamese twins. They were chirurgically separated by evolutive history but they always remember themselves and wish one another as one anew...
And my favorite music is acapela chorus....😁
Once this is said, Sibelius meant that music is beyond prosaic description as Poetry is beyond prosaic meanings ...
‘For me, music begins where words end’. - Jean Sibelius