Books and music: how do I pick my song?

So, you may have noticed that I usually listen to a song on repeat while reading a book. And if you're thinking, "What the hell is she talking about?", I always name it in the book info part of my review, in case you didn't notice. I'm not sure when this started, but since it's such a vital part of my reading experience, I thought I'd share it on here!

One of the earliest books I can think of when I started doing this was with Vampire Academy by Richelle Mead. It was Christmas of 2008. Little 9-year-old me ripped open a couple of my presents and found three books: Vampire Academy, Frostbite, and Shadow Kiss, all by an author I had never heard of. (S/O to my mom for being the real MVP, because that kick-started my obsession with the fantasy genre and badass heroines.) At the same time, I was obsessed with Akon, and had his album on repeat (the things I would do to get my hands on my old iPod oh my god), so I just started playing his music while reading VA. There was no thought behind it; I just put my headphones in. I'm not sure how I went from most of his album to two specific songs, if maybe I thought to myself "Let's play a specific song or two for just this book", and actually intended to start this trend, or what. But it happened, and Right Now (Na Na Na) and Troublemaker became my songs.
The songs never have to relate to the book. Sometimes they do, which is completely unintentional, and sometimes they really don't, and it's actually kind of hilarious. Case in point: my song for the Harry Potter series? Down on Me by Jeremih & 50 cent. 13 or 14-year-old Mariah was obsessed with that song and she had it on repeat while reading the first book, and it became the unintentional theme song. Should I even call them theme songs? I've never named it. I always just say something like, "This is the song I listen too while reading this book," or, "Yeah, this song is tied to blah blah blah."
Theme song is technically what it is, but that makes it sound like it's a 15 second song I play in the beginning or something.

Now what I do when picking a song is go by the actual sound of it. For example, I'm rereading The Raven Boys right now in preparation for The Raven King (as is half the country, which I'm LOVING). It's a serious process for me, and can take me hours to find one. I start by roaming through the songs I already have on my phone or Spotify playlists, and see if it fits with the mood of the book. Some songs instantly stand out to me and I think, "This is it" and it's done, boom, like that. I think it took me a little while to find a song for The Raven Boys, and I finally settled on Faith by Calvin Harris. I do a lot of EDM songs because, 1) I love them, and 2) they bring so much emotion and intensity to a book. Whenever the beat drops and I'm reading a pinnacle scene where the MC is fighting or making a huge decision... dear god, it's pure magic. I get instant goosebumps.
Faith was another unintentionally-relatable song:

"I need a little space in my mind
I need that little hope I can find
I need a little, I need a little faith
Is that too much to ask for?
I need to feel my soul come alive
I need to feel the strength to get by
I need a little, I need a little faith
Is that too much to ask for?"

The "I need to feel my soul come alive" line reminds me of Gansey, while the rest of the lyrics remind of something Blue or Adam would feel, with maybe a little dash of Ronan in there. It's rare for me to pick two songs, especially when I've already read a portion of the series, but there has been a few times when a song has literally smacked me in the face. I remember playing a snippet of How Deep Is Your Love by Calvin Harris on iTunes and it just screamed The Raven boys to me. I resisted, since I was already two books deep and thought it would be pointless, but it kept bugging me and bugging me and bugging me until, finally, I gave in. How Deep Is Your Love has that creepy, edgy, dark feel that haunts The Raven Cycle, and there's a specific part that reminds me painfully of Bluesey:

"I want you to breathe me in
Let me be your air
Let me roam your body freely
No inhibition, no fear."

As most of us know (this isn't a spoiler), Blue has been destined to kill her one true love with a simple kiss. So, I feel like this is something Gansey would think to himself when him and Blue are struggling not to kiss in his car, and instead are mashing cheeks and other awkwardly-funny things. He fears her kiss, but desperately wants to press his mouth to hers and breathe her in.

I was going to post all my top favorite books and the songs I picked for them but then I realized, duh, some of them are in my reviews, so I'm just going to name off books I haven't written a review for (a.k.a. all my favorites from before I started blogging).

WARNING: Some of these are random as legitimate fuck. Don't try and understand why I picked it. Younger me was eccentric in her music tastes!

The Mortal Instruments by Cassandra Clare // We Own The Night by Tiesto

The Infernal Devices by Cassandra Clare // Run by Kill It Kid

The Sky Is Everywhere by Jandy Nelson // Crawl by Chris Brown

Shadow and Bone by Leigh Bardugo // Where We Were by Pierce Fulton

Obsidian by Jennifer L. Armentrout // Sing by Ed Sheeran

The 5th Wave by Rick Yancey // The Monster by Eminem

The Book Thief by Markus Zusak // Losing My Religion (Glee Cast Version)

Stolen by Lucy Christopher // Jar of Hearts by Christina Perri

Wondrous Strange by Lesley Livingston // Now I'm That Bitch by Livvi Franc

I'll Give You The Sun by Jandy Nelson // We Are The Kids by Walk The Moon

Do you listen to any music while you read? If so, how do you pick the song? I'd love to hear your process or where you find your music!