In the next musical duel in Friday Night Funkin vs Javier, you will meet a new character named Javier Ukeston. He is a loyal fan of Funkin evenings, he follows the work of Boyfriend, but does not idolize him, unlike other fans.
Javier may be depressed, but that doesn't stop him from being one of the biggest Boyfriend fanboys in the world, and the fact that he can now challenge his idol in a musical battle is what brings him the greatest joy he's ever had, and he does not even matter if he loses, what he will lose because you will play BF and do your best to defeat him!
You have to do this until you reach the final score, and if the progress bar turns in your favor, you've become the winner, as simple as that. Don't miss too many notes in a row, or you too will lose the game. Good luck!