<!-- Page: https://rustic-game-engine.pages.dev/docs/api/audio/pitch -->

# Audio.pitch()

[Audio](https://rustic-game-engine.pages.dev/markdown/api/audio.md)

## Compatibility

**Supported languages:** C, C++, C#, Python, JavaScript, Lua 5.4, Luau, Java, PHP and HTML/inline JavaScript (binding spellings and return shapes differ).

Native devices and microphone input require Windows. Game-output recording and the mixer can run headlessly. Other operating systems do not supply the Windows native device backend.

The signature below is the shared reference notation; language examples show the actual binding syntax. Question marks mark optional arguments and explicit defaults are shown where recorded. Do not copy reference notation as a typed declaration.

See [Feature status and compatibility](https://rustic-game-engine.pages.dev/markdown/reference/compatibility.md) for API 1.0/1.1 and per-method restrictions. Engine release tags and Docs v0.1 are independent versions.

## Signature

`Audio.pitch(voice, value)`

## Setup and usage

These engine-owned services work in Lua 5.4, Luau, JavaScript, Python, C, C++, C#, Java, PHP, and HTML inline JavaScript. Follow [Use gameplay actions](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions.md) to create and attach a script, install external toolchains, and choose the correct language binding. PHP and HTML scripts belong under `ui/`; CSS alone runs no gameplay code.

The signatures and complete example below use JavaScript. Attach a JavaScript Object Component script to the specified target and press **Play**. Globals are supplied by the engine. Schedule actions from `Start` or a callback, rather than at script top level. Native languages use typed options and their own builder conventions; see the guide's language bindings.

## Parameters

| Parameter | Meaning |
| --- | --- |
| voice | Voice returned by Audio.play or Audio.playAt. |
| value | Finite positive pitch multiplier. |

## Return and timing

Updates the voice playback directly without creating an operation handle.

## Execution behavior

Core write timing differs between immediate Lua host calls, deferred JavaScript/Web commands and external SDK query flushes. Scheduled actions advance with the scene clock; synchronous queries evaluate at the call. Follow [execution rules](https://rustic-game-engine.pages.dev/markdown/guides/scripting.md#when-mutations-take-effect) and the return/timing notes for this category.

## Language examples

Choose one snippet at a time and place it inside your language's Start/on_start callback. These are independent examples; each creates its own handles or builders. Follow [Gameplay language bindings](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions/language-bindings.md) for imports and callback registration. Python must import the modules used in its snippet from rustic; C# uses using static Rustic; Java examples belong inside a Rustic subclass; PHP callbacks declare global $rustic. HTML snippets go inside an inline script in a ui/ HTML asset.

Use an anchored Part for transform and effect examples, an unanchored collidable Part for forces, and a perspective camera named Camera for camera examples. Create Target for follow examples. Audio examples require assets/music.ogg in the Play snapshot. Replace scene paths with those listed by Game.scene.List(). Animation playback and sequence-animation examples require the Reveal fixture on the [Animation page](https://rustic-game-engine.pages.dev/markdown/api/animation.md); marker callbacks also require its Halfway marker. Run clock controls separately; a paused clock cannot advance a timer.

C callback examples use these file-scope functions before on_start:

```c
static void on_done(void) { rustic.log("info", "done"); }
static void on_sample(RusticValue value) { (void)value; rustic.log("info", "sample received"); }
static void on_event(const RusticValue *args, size_t count) {
    (void)args; (void)count; rustic.log("info", "event received");
}
```

### Lua 5.4

```lua
local voice = Audio.play("assets/music.ogg")
Audio.pitch(voice, 1.2)
```

### JavaScript

```javascript
const voice = Audio.play("assets/music.ogg");
Audio.pitch(voice, 1.2);
```

### Python

```python
voice = Audio.play("assets/music.ogg")
Audio.pitch(voice, 1.2)
```

### C++

```cpp
auto voice = Audio::play("assets/music.ogg");
Audio::pitch(voice, 1.2);
```

### C#

```csharp
var voice = Audio.play("assets/music.ogg");
Audio.pitch(voice, 1.2);
```

### Luau

```lua
local voice = Audio.play("assets/music.ogg")
Audio.pitch(voice, 1.2)
```

### C

```c
RusticAudioVoice voice = Audio.play("assets/music.ogg", NULL);
Audio.pitch(voice, 1.2);
```

### Java

```java
var voice = Audio.play("assets/music.ogg", 1, 1, false);
Audio.pitch(voice, 1.2);
```

### PHP

```php
$voice = Audio::play("assets/music.ogg");
Audio::pitch($voice, 1.2);
```

### HTML / inline JS

```javascript
const voice = Audio.play("assets/music.ogg");
Audio.pitch(voice, 1.2);
```

## Shared Audio constraints

- Windows player output starts on the default audio device; `Audio.set_output_device` can change it. Other platforms currently mix PCM headlessly, so successful playback may produce no device sound.
- FadeOut reaches zero volume but does not stop the voice; stop explicitly or allow natural completion. Crossfade fades the old voice to zero and the new voice from zero to one.
- PlayAt attenuates distance relative to the active camera. The mixer renders 48 kHz stereo PCM with linear resampling for pitch.
- Clock scaling changes source playback rate; Clock.pause and voice.pause retain their source cursors. Natural completion releases non-looping voice PCM; loaded audio handles retain PCM until unload or owner cleanup. Stopping cancels voice-targeting actions on the next scheduler tick.
- Voices are owner-bound, with at most 1024 retained voices.
- Check script attachment, enabled state and the Console when an operation fails. Asynchronous errors also appear in operation state. Callback exceptions disable the owner and clean up its actions.
- Owner destruction, disable, successful reload or Stop cleans up owned actions and subscriptions. Failed reload retains the previous behavior's operations. See [Operation handles](https://rustic-game-engine.pages.dev/markdown/api/operation-handles.md) for controls and lifetime details.

## Errors and debugging

Read the constraints above and the Console diagnostic. Invalid types, non-finite values, stale targets or unavailable native services can fail validation. A failed callback disables the behavior; a failed source reload keeps the last good instance. Exact error messages depend on the language adapter. See [Troubleshooting](https://rustic-game-engine.pages.dev/markdown/troubleshooting.md).

## Related APIs

- [Audio.get_output_devices()](https://rustic-game-engine.pages.dev/markdown/api/audio/get-output-devices.md)
- [Audio.get_input_devices()](https://rustic-game-engine.pages.dev/markdown/api/audio/get-input-devices.md)
- [Audio.set_output_device()](https://rustic-game-engine.pages.dev/markdown/api/audio/set-output-device.md)
- [Audio.set_input_device()](https://rustic-game-engine.pages.dev/markdown/api/audio/set-input-device.md)
- [Audio.load()](https://rustic-game-engine.pages.dev/markdown/api/audio/load.md)

[All audio APIs](https://rustic-game-engine.pages.dev/markdown/api/audio.md)