Guitar Hero Live adds Rival Challenges
This is now available via the GHTV channels. Creative director Jamie Jackson explains, "As you play through the channels, you will periodically be matched up against a similar-skilled opponent to square off, 1-on-1 style, in a song battle to test your skills."
Rival Challenges become unlocked once you reach level 10. The developer says that this was implemented because at this point you have access to Guitar Upgrades and Hero Powers.