As repetitive as it is, for me, it's very addictive and very fun.
Some of the songs you pick are ridiculous to play. I mean, they make you go downhill almost constantly. Unless you're really good at this game, it's best to avoid those.
My friend on YouTube actually uploaded a vid of me playing the song Best of Friends with this. You really should check it out.
http://www.youtube.com/watch?v=Jh4cSr95IDwI'm not at the best of my skill, but I'd say it's still acceptable.
Love this game. Worth more than the $10 I spent on it.