If you are referring to the link that I have included in the OP, it should direct you to a livestream by this channel: https://www.youtube.com/@arteconcert which I believe is their main channel. Let me know if the link isn't working as intended
Arte Concert is not the main one. Its only for the Concerts that were recorded with the help of Arte.
since they are multinational they don't really have a main channel.
https://www.youtube.com/ARTEde is the German part and https://www.youtube.com/arteplus7 is the french part of their productions(German and french public broadcast are the owners and pay each 50% of the budget, plus a numerous public broadcast companies coproduce various movies and shows).
Oh, thanks, I see what you mean now. I will see if I can rename this submission to make it clear it's not the main Arte channel.
EDIT: it doesn't seem I'm able to rename the thread, sorry.
The German channel also appears to have been hijacked.