# Diegetic sound > Sound that comes from inside the story's world, so the characters can hear it: dialogue, a car radio, a band in the room. Non-diegetic sound is added for the audience alone, like the score or a narrator talking to us. Also known as source sound, source music **On the page** ``` A jukebox plays a slow country song. The song cuts out mid-chorus. ``` ## In practice The word comes from diegesis, Greek for narration, which film studies uses for the world of the story. The test is simple: could a character in the scene hear it? A song on the jukebox is diegetic; the strings that swell when the couple finally kisses are not. On the page, diegetic sound belongs in action, because it is part of what happens: the radio plays, the phone rings, the crowd starts chanting. Name a specific song only when the scene turns on it, and expect it to change once rights are cleared. Leave the score out; it belongs to the composer and the edit. The best moments sit on the line between the two. Music can start on a car radio and swell into score, or score can resolve into the record the hero lifts the needle from. A pre-lap carries sound across a cut. Write the shift you want the audience to feel in a sentence of action, and let post find the means. ## See it formatted - [V.O. versus O.S.: which screenplay extension should you use?](https://www.inkwell.software/resources/screenplay-formatting/voice-over-versus-off-screen): Use O.S. for a speaker who belongs to the current scene but is outside the frame; use V.O. when the voice comes from outside the scene's immediate physical action. - [How to format a pre-lap in a screenplay](https://www.inkwell.software/resources/screenplay-formatting/pre-laps-and-sound-bridges): When the next scene's sound arrives before its picture, write it just above the scene it belongs to: a (PRE-LAP) cue for a line of dialogue, a PRE-LAP line in action for a sound. - [How to format song lyrics in a screenplay](https://www.inkwell.software/resources/screenplay-formatting/songs-and-lyrics): Set sung lines apart from speech — italics or all caps, one lyric line per line — and quote only the lyrics the scene actually needs. - [Should sound effects be in all caps in a screenplay?](https://www.inkwell.software/resources/screenplay-formatting/sound-effects-and-capitals): Capitalize a sound, prop, or action only when it has to jump off the page, and a speaking character's name at first appearance, so capitals still mean something. ## Common questions ### What is the difference between diegetic and non-diegetic sound? Diegetic sound exists in the story's world, so the characters can hear it: dialogue, footsteps, a radio, a band. Non-diegetic sound is for the audience only: the score, a narrator speaking to us, effects added purely for emphasis. ### Should I write music in a screenplay? Write music the characters hear when it matters to the scene, in action. Leave the score out. If a particular song is essential, name it once and be ready for it to change, because licensing decides what reaches the screen. ### Is voice-over diegetic? It depends on who can hear it. A narrator talking to the audience is non-diegetic: nobody in the scene hears the narration. A recording, a radio or a caller on speakerphone is diegetic, even though screenplays usually mark it V.O. too, because the speaker is not in the room. A character's thoughts sit between the two: they come from inside the story, but only that character hears them, which film studies calls internal diegetic sound. The extension says where a voice comes from; diegesis says who can hear it. ## Related terms - [Voice-over (V.O.)](https://www.inkwell.software/glossary/voice-over): Dialogue heard but not spoken aloud in the scene's space at that moment — narration, a remembered voice, a character's thoughts, the far end of a phone call. Marked as (V.O.) on the character cue. - [Off-screen (O.S.)](https://www.inkwell.software/glossary/off-screen): A character who belongs in the scene’s space but is not visible in the shot — calling from another room, speaking just out of frame. Marked as (O.S.) on the cue. - [Pre-lap](https://www.inkwell.software/glossary/pre-lap): Sound from the next scene — a line of dialogue, an effect, or music — that begins before the picture cuts to it, written just above the new scene heading. - [Montage](https://www.inkwell.software/glossary/montage): A run of short beats or shots in quick succession — often under a MONTAGE heading — used to compress time or braid parallel action. --- Canonical page: