Abelard's planctus for Samson and Delilah uses the biblical narrative as an occasion for meditations on loss and betrayal that resonate with his own catastrophic relationship with Héloise, showing how the Latin planctus could encode personal suffering within biblical subject matter; The planctus of Mary at the foot of the Cross, the Stabat Mater tradition, is among the most widespread forms of medieval devotional poetry, expressing the Marian lament in forms that range from simple Latin stanzas to elaborate polyphonic musical settings; The planctus of Charlemagne for Roland in the manuscript tradition of the Chanson de Roland adapts the Latin funerary lament to the vernacular epic context, showing how the genre migrated between Latin and vernacular, sacred and secular literary spheres; A student comparing the planctus with the vernacular complainte should observe how the Latin sacred context shapes the planctus's imagery and rhetoric: its appeals to God, its meditation on sin and redemption, and its framework of Christian hope distinguish it from the more worldly grief of secular lament; The planctus's musical dimension is inseparable from its poetic content: the surviving melodies set the Latin texts in modes associated with solemnity and grief, creating an acoustic environment for mourning that reinforces the verbal expression of loss; The genre's transformation from ancient Roman funeral laudation through early Christian martyrology to medieval planctus reveals how the Western tradition of formal mourning continuously adapted inherited forms to new theological and cultural contexts.