The first occurrence.
Then sang Moses and the children of Israel this song unto YHVH, and spoke, saying, I will sing unto YHVH, for He has triumphed gloriously: the horse and his rider has He thrown into the sea. Exo 15:1
The primitive root.
shin ש = two front teeth, thus sharp, press, eat, two, again
yud י = the closed hand, thus work, throw, worship
resh ר = the head of man, thus head, first, top, beginning, man
The story: In the patriarchal era, a cord was made when two (shin) strips of leather or sinew were attached at the top (resh) and then twisted together in such a fashion so as to lock their fibers. When the hand closed upon (yud) the cords (shin + resh) of varying widths, and plucked them, music was made to accompany the singing voice.