Final verdict? I liked it. I actually liked it far more than I was expecting to based on my initial thoughts:

First 50-60% of the book? Maybe 1 and a 1/2 stars...
Last 40 - 50% of the book? Probably 4 stars. I was definitely surprised how it turned around for me.

Initial thoughts at 17% of the way through the book:
"I am not into this one. I feel like the author believes everything has to be funny and that teenagers only speak in sarcasm. Everything comes second to the witty one liners.
I didn’t even know Sophie was actually in the band she’s fundraising for until she told August what she played at a party, like six or seven chapters in. I remember now she mentioned when practice started in the summer, but it wasn't a detail that stuck."

At the end of the book:
The characters really did it for me. I came to actually love Sophie and Flora, and I already kind of liked Brit but I wound up loving her too. August was alright. But this was so much more about the friend group than it was a romance, even if the first chapters didn't promise that. This is actually a book that didn't live up to it's promise and I'm SO GLAD it didn't because the book the first few chapters promised was so full of tropes and felt hokey and contrived. I felt like the author had never been in band and probably hadn't talked to anyone in band and I was pretty stuck on that. That and NO ONE parties that much, not even in the summer, and especially not band kids.

I really liked the ending of the whole Megan Pleasant drama, not to give any of that away. Also, I was pretty blindsided by a couple of reveals, so that was nice. I'll definitely read more of this author's works.