If you remember well this is something I was wary about, I mean, it's supposed to be about a music club, you can't really help but find similarities to K-On, which strangely enough I did find entertaining.
So yeah, Tari Tari is about a girl whose dream is to sing, unfortunately she's ostracized by the evil vice-principal (somehow those are always evil in anime, or nearly) from the choir club and since she can't sing in it, well, she quits. After all what's the point?
So obviously being an annoying little brat she can't help but continue singing anyway, that's what an heroine should do after all.
To be honest, there's nothing much to say about this, in that aspect it's like K-On, it's just about cute people (yeah because there are boys in this and one of them is moe as hell) doing cute things at school.
Where it differs from K-On, aside from the character design, is that it does seem a bit more mature and realistic. Things don't always go as well as they do in K-On, in that sense Tari Tari's probably for people who can handle seriousness in their anime.
Characters seem like they're going to have a bit more development and well, it has boys! Can you believe it?
It seems like it'll be an interesting thing to watch, the first episode flows pretty nicely, nothing really feels forced, aside maybe from the main character who's a bit too over the top for me.
Definitely on my watch list!