Just re-sampled (not really re-reading it, just skimming a bit and recalling having read it as a lad) a classic Andre Norton and ran across,
“Nick could not tell whether it was singing or music. . . “
*groan* See Inigo Montoya. I do not think those words mean what she thinks they mean. Not all music is singing, but all singing (though not all that is called singing, especially nowadays) is music.*sigh*