A Well Respected Man - The Kinks
Darcy knows Arthur's not conservative. He's actually really liberal, even if his posture and clothing screams otherwise. However, she's pretty sure she can count the days she's seen him disheveled and out of sorts since she got to the orphanage when she was nine without using her toes.
Lady - Regina Spektor
He thinks he's hiding something when he reads tragedies and listens to operas that would send Ginny crying into her pillow, but they all know he's got a soft spot for a tragedy and the blues. Darcy knows it's going to get his heart broken someday.
What I've Done - Linkin Park
Darcy doesn't add this one to the list until after Ariadne has cracked a little around the edges and written secrets on a chalkboard in a dream with her.
Colors of the Wind - Pocahontas
It was a joke Jake and Temp started to cheer her up a little before Temp's imminent departure for the Army, but it stuck and they all got their own Disney songs. Arthur's was meant to make him pause and take a look around sometimes.
My Manic and I - Laura Marling
So maybe Darcy's more than a little put out he never sends a note with her Christmas or birthday gifts and doesn't show up himself. She listens to this song and wonders if he's got a girl crazily devoted to him.
Rock 'n' Roll Delight - Hugo
They sang along with it together, just the two of them, on the way back to the orphanage from sending Jake off to basic. Neither of them calls the other on their tears.
Pumped Up Kicks - Foster the People
Just like with the conservative thing, Darcy knows Arthur wasn't the type of guy to take a gun to school, but sometimes when he was quiet after all the others were gone she wondered if they hadn't been there if maybe he might have been.
The Alternative - IAMX
Darcy added this one to Arthur's list because she thought it felt like him: kind of slinky and sly in a classy way always talking about things that you can pretend to understand, but couldn't repeat back intelligently to save your life. Later, sometime after that dream with Ariadne, Darcy pretty much decides her playlists are psychic.
Bad Romance - Joseph Gordon Levitt (Lady Gaga cover)
She knows the next time Arthur gets drunk with her around he'll be taking her camera phone.
Secrets - One Republic
Neither Darcy nor Ginny hear a word from him for over three years. They get fabulous birthday and Christmas gifts, but end up trying not to cry on the phone with each other about it anyway.