One of the last hair metal bands in America must battle changing musical trends and a shadowy corporate adversary on their quest to reach L.A. and rock n roll stardom.

THE HARDER THEY FALL -
After the Seattle grunge scene takes over and a lauded hair metal band loses relevancy overnight, the cocaine fueled-narcissistic lead singer engages in a publicity stunt that lands him in jail where he turns his life around with the help of a mysterious reformed murderer.

This is too vague.
You need to describe specifically what the inciting incident is;
What does "...must battle changing musical trends..." mean? What is the specific event in which they do that?

You also need to describe specifically what the goal is:
What does "...rock and roll stardom...." mean in practical terms? What single objective do they need to achieve?

Lastly, why? What is at stake if they fail?