Excuse my rare appearance.
A few more info:
1. Yes, these were kingdom songs. Specifically, it was song 99 and 139.
2. In total, 6 talks from Berlin were streamed. Among other things, the baptism talk and the closing talks.
3. At these conventions with delegates from other countries, it is not uncommon for people to sing, dance and make music in the breaks. But all this takes place outside the stadium. This time it was inside the stadium. It was like the folks decided to expand and alter the programm on their own.
Personally, I found it very remarkable that the JW organized themselves within a day to do something Bethel did not like. For a critical thinking JW it is remarkable because bethel (and especially German bethel Selters) want to be in control of every single part of the convention. Sorry, if you do not see it that way and and don't look at it as hot news.
So here is a video from youtube: https://www.youtube.com/watch?v=EvY2f7dLbkI&t=188s