The Sky is Everywhere by Jandy Nelson
Perfect condition
 
Adrift after her sister Bailey's sudden death, Lennie finds herself torn between quiet, seductive Toby—Bailey's boyfriend who shares her grief—and Joe, the new boy in town who bursts with life and musical genius. Each offers Lennie something she desperately needs... though she knows if the two of them collide her whole world will explode.

Join Lennie on this heartbreaking and hilarious journey of profound sorrow and mad love, as she makes colossal mistakes and colossal discoveries, as she traipses through band rooms and forest bedrooms and ultimately right into your heart.