I love so much of the music... Sadly I don't know all the episodes or song names, but I'll try.
"Welcome to my head" by Thunderpuss when Justin is drawing after Cody stirred his post-bashing trauma up again. That scene was so incredibly powerful and the song is perfect.
That chorale song that is played somewhere in 509 when Brian hallucinates that Michael comes to Babylon. It was like a serenade to farewell Babylon as it is, because it's bombed in the next episode. It was so haunting, I got the shivers.
Also, 402 when Emmett is back at Babylon, dancing to "Mundian To Bach Ke" by Punjabi MC. I was so happy he was back ♥
Then, who could forget "Straight to number one"? Whenever I hear it, I think of the reverence and adoration on young Justin's face. Sigh.
When Justin goes back to the loft in 301 to get his things. The song is just so beautiful and makes me so sad, coupled with the shower scene...
The way they blended Babylon's clubbing music with Ethan's violin until it's only the violin as Michael tells Brian that Justin's seeing someone. It breaks my heart, but I could watch that scene over and over and over. Hauntingly beautiful.
And the beginning of 312! It's one of my absolute favourite club scenes because the music is great and the way it's shot is just amazing. I adore it like no one's business.
And don't forget "Cha Cha"! How it starts out with glimpses and then comes the deep, dirty beat and BAM! You've got Justin and Brian dancing in slow motion.
And the song at the end of 314! So beautiful.
Okay, I'd better stop now, my family needs the computer, haha. I could go on for ages!