The etymology of the word plangent is fascinating. This word with mournful connotations takes its origin from the Latin plangere which translates as the lamentations of beating the breast. The word is used a great deal in describing music but can be used with a sigh to talk about calamitous political situations and emotional dramas.
Here are some literary instances of the word:
“Sarcasm and jokes were often the bottle in which clinical depressives sent out their most plangent screams for someone to care and help them.”
“To this waltz, born in a distant, snowbound country out of longing for just such a flower-scented summer night as this, Rupert and Anna dance. They were under no illusions. The glittering chandeliers, the gold mirrors with their draped acanthus leaves, the plangent violins might be the stuff of romance, but this was no romance. It was a moment in a lifeboat before it sank beneath the waves; a walk across the sunlit courtyard towards the firing squad. This waltz was all they had.”