so I'm translating an RPG book from English to Brazilian Portuguese and stumbled upon (for the first time) with the expression "strident note". I'm not familiar with it, and although I can sort of grasp the overall idea of the excerpt where it appears, I wanted to have a better understanding of its meaning, but my attempts to google it returned no results with its meaning, just examples of usage.
Can anyone help me? Here's the excerpt:
"Ana's ultimate goal is to persuade her husband to use his authority to have the cigani identified as an undesirable pagan influence on [...]. Unfortunately, Father Filopovic is a more tolerant man than she had anticipated, and a strident note has entered her calls to eject the cigani."