Play/Pause multiple audio tracks along a timeline

you need a closing </audio> tag. This has more info: <audio>: The Embed Audio element - HTML: HyperText Markup Language | MDN

No. A class is inside of class="X" and an id would be within id="x"

Sharing a document with these tests sertup would be great so we can see exactly what you're doing.

This should work as long as you don't have any scene transitions (instant transition only).

You're 'engaging in media' so the browser is thinking 'hey, this guy really wants to play sound'. Chrome calls this the Media Engagement Index. But you may see different behavior in different browsers when it comes to this. Sometimes this engagement is linked to what you do on a domain.

You can probably play quiet static as an on scene load action until the browser algorithms become self aware :ghost: