The Master of Demon Valley

The mouth is the door of the mind; the mind is the host of the spirit. Will, intention, joy, desire, thought, worry, knowledge and planning all go in and out through the door. - The Master of Demon Valley.

This is an ancient Taoist text which was translated by Thomas Cleary some twenty years ago and it tells of how Taoist thought and philosophy of ‘the way’ could be used to influence and control the population.
The premise is that all things move from masculine active to feminine receptive or as they express it as Yin and Yang the Yang being the masculine. Language is used to develop that depending on where you are in that arc and not so much about the reality of language expressing truth as we think of it; more in a way of language as a form of magic and spell casting.
The similarities with NLP are interesting with the language being seen as fluid and influential to the mind of the listener.
So if you want to write a rousing song use rousing words, something about love keep saying love, a song about anger, use words that express anger even if they do not make sense in a literal way use language’s power of poetry.