Can I stream Just Dance or Rockband, etc?

The best answer we can give is: Maybe.

These games often have the music within them licensed specifically for individual private use of the of the music for the game. It does not always cover streaming the game. (Which is true for any in-game music. It may not be licensed for streaming.)

Check the game’s EULA. Hopefully the game has an online page on their website stating what songs are or are not approved to play online in live streams or videos.

Some games, like Beat Saber or Synth Riders have user curated playlists and levels. These may or may not be licensed for streams.