It's a great look at the music scene of the period, punk, new wave, even a little reggae and while it's definitely low-budget, it's got a lot of that great 70s pseudo-realism that was about to disappear completely in the 80s. It was written by Nancy Dowd (Slapshot) and Jonathan Demme. Oh yeah, and Christine Lahti gives a great two-scene performance as Dern's mother.
I don't want to give the story away, but it's easy to see how this 1981 film was an influence on the riot grrl phenomenon and a whole generation of female rockers. And the White Stripes almost certainly got their name from a line about Diane Lane's hairstyle.