I'm feeling a little better about this whole synopsis thing. This revision sounds more like the tone and wording in the manuscript instead of like a combination of Seth and me. I tried to play up the Rosetta love stuff while subtly adding to the economic/social class issue for a little more tension.  I'm having a hard time making the sentences flow and transition, but it's getting better.  My punctuation is still a disaster, I'm sure.  :-) 

The Fake McCoy
The “trailer trash” label sixteen-year-old SETH MCCOY gets from assholes like CARR sucks. But Seth agrees that he really does have only one thing going for him: he can play the hell out of a bass. Getting wasted before gigs was Seth’s way of keeping his stage fright in check. In fact, alcohol was his way of coping with everything shitty in his life. But finding his friend, ISAAC, dead after a night of partying two months ago caused Seth to give up drinking. 
Now, Seth’s band—The Real McCoys—is being given an amazing opportunity to tour as an opening act. The rest of the guys are stoked, but Seth panics.   Even though he hates letting everyone down, he bails—quitting the band is his only shot at staying sober—leaving the others scrambling to find a new bassist.
Soon after, XANDER from school asks Seth to join his band. Seth isn’t sure he’s ready, but these dudes are laid back and seem to be in no hurry to do the live gig thing. A no-pressure music project is what Seth needs right now, so he agrees to play with them.
In the meantime, Seth gets stuck on a school project with the girl Carr wants, ROSETTA.  Seth and Rosetta couldn’t be more different. Rosetta lives on Rich Bitch Hill; Seth’s from Riverside Trailer Park. She hopes to play professional golf someday; he thinks of golf as something to watch on TV when he needs a quick insomnia remedy. She’s a brainiac; his report card has more ‘Ds’ than a Victoria’s Secret model’s lingerie drawer. But it doesn’t take long for them to see they have something in common after all: they both have intense guilt. Seth blames himself for Isaac suffocating on puke; he didn’t even think to turn Isaac over when he passed out on his back. Rosetta holds herself responsible for the crash that killed her parents because she was behind the wheel and didn’t react quickly enough to avoid the collision. 
When Xander books a local gig, Seth confides in Rosetta and asks in all seriousness whether he should give up his new band or his sobriety. She believes he can keep both. He’s surprised and touched by her confidence in him and, while they work together to overcome their fears, Seth and Rosetta fall for each other.  Her friends don’t get it, but Seth and Rosetta don’t care—until Carr, in his jealousy, leads Rosetta to believe that Seth betrayed her. Pissed and confused with Rosetta wanting nothing to do with him, Seth goes after Carr for a fight that’s been a long time coming. It ends with Seth getting an ass kicking and a five-day suspension from school. 
Losing Rosetta is like losing everything. Seth deals by swiping booze and getting hammered. As he’s on his knees, puking in the very spot where Isaac died, he has a moment of clarity. This definitely isn’t what he wants to do with his life or the person he wants to be. After sobering up, he goes to Xander and the guys and talks to them about his stage fright. They are supportive and come up with chemical-free ideas to help Seth perform with less anxiety.  Later, he heads to a party, hoping to meet up with Rosetta so they can talk. Instead, he finds Carr passed out on the floor. Seth starts to leave, but goes back and turns Carr onto his side.
On the night of the gig, Seth is onstage, nervous as hell, but ready to do this. He sees Rosetta smiling up at him in the crowd. After everything, she still came to see him. Seth smiles back, sure now that they’ll be able to work things out. And then he starts to play.