WAN 2.7 generates a soundtrack with the video. Describe the soundscape you want in the positive prompt: dialogue, ambient tone, specific sound effects. "Sounds of distant water and gentle wind" or "the espresso machine hisses in the background" both read cleanly.
Music is a positive-prompt control, not a negative-prompt one. Keep music terms out of the negative prompt. To keep a scene music-free, add the phrase "No background music." to your prompt. To get music, ask for it explicitly, like "suspenseful background music."
For spoken dialogue with lip-sync, write the action sentence first, then the line in this format: [Name, tone]: "line". Example: The agent slams his hand on the table. [Black-suited Agent, angrily]: "Where is the truth?"
Give every speaker a unique name and never tag a line with a pronoun. WAN matches each line to a character by name. Short single-speaker lines under 10 words sync best.