I use YTD Video Downloader https://www.ytddownloader.com/
This will download any Youtube video (you frequently have to update the free version, declining the paid update if you wish) for all files to download...maybe once every few months.
It saves the whole video on your disk but then has a convert tool to make an MP3 out of the video. That seems much easier than what you describe to get the audio file for the ACW.


Embarked devotee of "Band in a Boat"