This playground is a live-editing environment for exploring Elementary and making sound. Start by enabling the audio runtime with the play button in the bottom control panel. Afterwards, the runtime will automatically update as you edit.
As a general guideline, you can write anything you like as long as it's an ES6 module with a default export object containing at least a render() method. This method will be invoked upon evaluating your code to update the running state of the audio runtime.
For more information, check out the Playground API Reference, or load some examples: