Let’s use <iframes provided by archive.org

<iframe src="https://archive.org/embed/losenfants" width="500" height="30" frameborder="0" webkitallowfullscreen="true" mozallowfullscreen="true" allowfullscreen></iframe>

Embed audio playlist

Embed audio playlist with specific list height

Archive.org player with multiple files and a cover image

Idem ^ + Embed audio playlist and specific list height

Idem ^ without specified height

Loading a file with HTML <audio>

Listen to the T-Rex: