Dirty Little Secret by Jennifer Echols (MTV Books, 16 July 2013).
Bailey Mayfield grew up playing bluegrass music all over the southern States, along with her younger sister Julie. At sixteen, Julie got a recording contract. By herself. Without Bailey.
Because Bailey handled the news badly, her parents sent her to spend the summer with her grandfather, while they toured with Julie. They even made her use her mother's maiden name: Wright. Bailey's not supposed to perform because she might "mess things up" for her sister, but her grandfather got her a job playing the fiddle for a company that provided musical impersonators for various events.
After a few days of playing the fiddle in cheesy costumes with "Elvis" and "Dolly", she's assigned to play with a Johnny Cash impersonator, Darren Hardiman and his son, Sam. Not only is Sam incredibly gorgeous, he's an amazing guitarist and singer. After their gig, he asks Bailey if she wants to play a gig with his band at a bar that night, but when she asks her grandfather, he immediately refuses.
But Sam won't take "no" for an answer, and shows up on the doorstep telling Mr. Wright that he wants to take Bailey out on a date. Bailey's grandfather is so charmed by Sam that he agrees, and they sneak Bailey's fiddle out with them.
Bailey fits in great with the band, musically, anyway. Charlotte, the drummer, who went to high school with Sam is jealous of her, and the bass player, Ace, dislikes her because Charlotte does.
Bailey is terrified that someone will recognize her, or that her family will find out. And she's embarrassed to tell the band why she shouldn't join them.
Echols is very good at portraying strong young women in difficult circumstances (see last summer's Such a Rush). We learn about Bailey's family and history organically, as the story unfolds, which makes her situation even more poignant and bleak. I do, however, have an issue with the title, which makes Bailey's "secret" seem like something dark and sordid, which it really isn't.
FTC Full Disclosure: Many thanks to the author for the advanced reading copy.