Gretta went to the city with her boyfriend Dave hoping they would make it big. Dave did and then he dropped Gretta.
She was later on discovered by Dan (a divorced obsolescent record producer) in an "open mic" bar.
Just like Coyote Ugly, the heroine started from the lowest point in her life but slowly getting on her feet until reaching her dream.
I think the only good thing about this movie is that Keira Knightley has a nice voice.