The vaar is the Punjabi heroic ballad, sung in a specific rhythm to a dhad and sarangi or to a drum, celebrating a battle or a man who died in one. It is older than any written Punjabi.
Guru Arjan Dev Ji, compiling the Adi Granth, directed that certain compositions be sung to the tunes of named popular vaars of the day: the vaar of Tunda Asraja, of Rai Kamaldi and Mojdi, of Sikandar and Ibrahim. Those instructions are printed in the volume above the compositions and are the only surviving record that those ballads existed.
That is a deliberate act of preservation and appropriation at once. The tunes of secular war songs carry hymns.
The form continued outside scripture. Najabat's Nadir Shah di Vaar, Shah Mohammad's Jangnama, and the dhadi repertoire on the eighteenth-century martyrs are all vaars.
This site borrows the word for its chapters, because a vaar is what an account of a place and its dead is supposed to be called in this language.
The vaar is the heroic ballad: a sequence of pauris with a fixed rhythm, sung by dhadis, describing a battle or a life, with the crowd expected to respond.
The Guru Granth Sahib Ji uses the form for something else entirely. Twenty-two vaars in it take the metre of the battle ballad and put a spiritual argument in it, and several carry the tune of a known secular vaar as their heading.
That instruction, to sing this to the tune of that vaar, is one of the few pieces of evidence about what Punjabi popular music sounded like in the sixteenth century.