(1) The tilde over the letter o is a dead giveaway as the other languages don't have it.(2) A tilde over the vowel indicates a high broken tone, in which the voice starts slightly above the middle of the normal speaking voice range, drops and then rises abruptly.(3) In modern Paraguayan orthography, the nasal vowels are represented with the nasal tilde (~) over the oral version of the vowel.(4) The fact that the singer was Spanish and that the programme printed the song title with a tilde might have been a clue, anyway.
