In most of Andes ' towns `` vamos a ir a la quena '' ( we will go to the quena ) was used to threaten little children , because the quena was made of bamboo , a hard material . In most of Andes ' towns `` vamos a ir a la quena '' ( we will go to the quena ) was a popular sentence to threaten little children , because the quena was made of bamboo , a hard material .