The best way to get correct ID3-TAGS should look like this:
1. Check if there's "Music in this Video". If yes get the tags from there, if no go to 2.
2. Check if Videotitle matches the structure ".... - .... ". If yes get the tags from the title as [Artist] - [Title]. If no go to 3.
3. Set Channel-name as Artist and Videotitle as Title.
This should get the correct ID3-TAGS in 99% of all Music on YouTube.