Understand sound and music design, including the functions of sound, diegetic and non-diegetic sound, and how sound creates mood, place, time and meaning

What this dot point is asking

SEAB wants you to understand sound and music design: the functions of sound, the difference between diegetic and non-diegetic sound, and how sound and music create mood, place, time, tension and meaning. You should be able to list the functions of sound, define and give examples of diegetic and non-diegetic sound, and explain how sound choices shape the audience's experience. The central insight is that sound and music are among the most powerful tools for reaching the audience's feelings and locating them in a world: they set mood, establish place and time, build tension, mark structure and carry meaning, and a key distinction is whether a sound belongs inside the world of the play (diegetic) or exists only for the audience (non-diegetic).

The answer

Why sound and music matter

Sound and music are powerful design tools that shape the audience's experience directly and often unconsciously. Sound reaches the emotions quickly: a few notes of music or a single effect can set a mood, locate a scene, or build dread before anything is seen. Because hearing is immediate and emotive, sound is one of the strongest means of creating atmosphere and meaning. A piece that uses sound deliberately gains depth and feeling, while one that ignores it misses a major opportunity, so sound design deserves the same care as the visual elements.

The functions of sound and music

Sound and music perform several functions. They create mood and atmosphere, such as eerie music for fear or warm music for comfort. They establish place and time, such as birdsong for a garden at dawn or traffic for a city street. They build tension, through a rising drone, a heartbeat or a ticking clock. They mark structure and transitions, using music to link or separate scenes. They carry meaning, through a motif associated with a character, place or idea that returns to signal it. And they support action, such as a sound effect for an offstage event the audience cannot see. Recognising these functions lets a group use sound purposefully.

Diegetic and non-diegetic sound

A key distinction is between diegetic and non-diegetic sound. Diegetic sound comes from within the world of the play and can be heard by the characters: a radio playing on stage, a doorbell, a phone ringing, or a character singing. Non-diegetic sound comes from outside the world of the play and is heard only by the audience: background music underscoring a scene to set its mood, or a sound effect added purely for the audience's feeling. The simple test is whether the characters can hear the sound. The distinction matters because it determines how the sound functions and how the characters and audience relate to it.

Choosing diegetic or non-diegetic

A group chooses between the two based on what they want the sound to do. Diegetic sound grounds a scene in a real environment, makes the world feel solid, and can be reacted to by the characters, so a ringing phone can drive the action. Non-diegetic sound shapes the audience's feeling directly, without the characters being aware, which makes it ideal for setting mood, underscoring emotion and emphasising a moment. Some pieces blur the line deliberately for effect. Understanding the difference lets a group decide whether a sound belongs in the world of the play or exists to guide the audience, and use each for its strengths.

Designing sound for effect

Effective sound design, like lighting, is deliberate and matched to the action and intention. The volume, timing and quality of a sound all shape its effect, and the same sound can be reassuring or threatening depending on how it is used. Silence is a sound choice too, and a sudden silence or the absence of expected sound can be powerful. Sound works closely with the other elements, so a designer chooses sounds that combine with the lighting, the staging and the performance to build the intended mood, locate the scene, and carry the meaning. The aim is always the effect on the audience, so every sound should earn its place.

Examples in context

Example 1. Non-diegetic dread. A scene of a character walking home alone is underscored by a low, growing drone that the character cannot hear but the audience feels building. The non-diegetic sound creates dread directly in the audience, warning them of danger the character is unaware of, and shows how sound shapes feeling without belonging to the world of the play.

Example 2. Diegetic sound that drives action. A tense family scene is interrupted by a phone ringing on stage - a diegetic sound the characters hear and react to. Who answers, who refuses, and what the call brings drive the scene forward, showing how sound that belongs in the world can become part of the action rather than only setting mood.

Try this

Q1. Name four functions of sound and music in drama. [3 marks]

• Cue. Any four of: creating mood and atmosphere, establishing place and time, building tension, marking structure and transitions, carrying meaning through motifs, and supporting offstage action.

Q2. Explain the difference between diegetic and non-diegetic sound, with an example of each. [3 marks]

• Cue. Diegetic sound comes from within the world of the play and can be heard by the characters, such as a radio or doorbell; non-diegetic sound comes from outside the world and is heard only by the audience, such as underscoring music; the test is whether the characters can hear it.

Q3. Explain why a group might choose non-diegetic music to underscore an emotional scene. [4 marks]

• Cue. Because non-diegetic sound shapes the audience's feeling directly without the characters being aware of it, underscoring music can set or heighten the emotion of a scene and guide how the audience responds, which is useful for mood and emphasis in a way that a sound belonging to the world of the play could not achieve as freely.