First moments of the game: As a general rule, never put text on the screen to read WHILE lyrics are being sung. That's two different sets of words being pushed into your player's face right from the get-go. This continued throught - it's very hard to read the note I picked up when some girl is singing at me.
Long story short: either don't have text in your game, or change the music to something without lyrics.
The second song is better, but too intense and fast-pased considering I'm solving some sort of alphabet soup puzzle. It's not fitting for the situation.
I couldn't figure out that puzzle, by the way.