In the course of their development, Tibetan folk songs provide a valuable record of history, social life at various times and social conditions as well as the general development of art and culture in Tibet. Even in the days when the Tibetans has no scrip folk songs were widespread in the style of oral literature, while after the invention of a writing system together with the consequent acceleration of social and cultural development, folk songs were also enriched by the newly literature, while after the invention of a writing system together with the consequent acceleration of social and cultural development, folk songs were also enriched by the newly literate.
Ancient documents in Tibetan show that Tibetans often used folk songs to express themselves. According to an account discovered at Dunhuang, at the time of the thirty-first Tubo Tsanpo Takri Nyansik, two ministers of the Sumba people named Wa Yitsal and Nyang Tsenggu pledged allegiance to the Tubo Tsanpo in this song:
Yonder o'er this river,
Yea, yonder o'er the River Tsangpo,
There is a King, Sent from Heaven it seems,
Who rules over the land.
He sits well with the people
As a saddle sits well upon a horse.
The two ministers hid themselves in groves by day and entered the palace of Chingwar Taktse as night fell, and there they offered their vows of allegiance.
On seeing this, the people sang:
Two strong men and two strong steeds,
Hiding in the groves by the daytime.
And sneaking into the Chingwar as the night falls,
Wonder who they be, foes or friends?
From this it is clear that from the sixth century at least folk songs were commonly used in place of speech. At the time of Takre Nyansik, (enthroned 610 AD) however there was still no writing system and therefore all folk songs in circulation were oral creations of the people, plain and simple in style, and as yet exhibiting no sophisticated artistry.
But following the introduction of a Tibetan script, great changes began to take place. The emergence of metaphor made folk songs more vivid and artistically enriched. Note the use of analogy and metaphor in this song taken from an account of Tridrug Songtsan (enthroned 676 AD) in Historical Documents of the Tubos Discovered at Dunhuang. When the Tsanpo realized that his ministers were plotting to murder him and seize the throne, Tridrug Songtsan sang in his rage: