
This is in no way tutorial, but I want you to know that I’m using yt-dlp to download stuff from YouTube directly.
I use my script (below) to download the audio that goes with the video Madeleine Dring – Trio for Flute, Oboe and Piano (1968)(with full score:
youtube-dl-audio https://youtu.be/Q4wzM9kcqNg

My script is youtube-dl-audio is this (it calls yt-dlp to do the work):
#!/bin/bash
yt-dlp --verbose -x --audio-format mp3 $1
yt-dlp will download the actual video file, then use ffmpeg to split off the audio portion for you.
To download the video file itself:
yt-dlp https://youtu.be/Q4wzM9kcqNg