Old tv series please help?

i'm looking for a old tv show where a red head girl wins a contest and becomes a rock star and i cant remember the name or who's in it at all all i know is the red girl wins a contest at her school and becomes a rock star then she falls for some older guy who used to be in a boy band and her sister hates her i think the guys name was Tommy but I'm not sure so if you know what I'm talking about great if you don't sorry i don't know more