I am so excited they released the awesome song we've all been waiting for and so here's an OST list for the songs so far:

OST part 4

Seol Hoseung (SURL) - Break Through

https://www.youtube.com/watch?v=ZmjN9Zo_skU

Orchestra version: https://www.youtube.com/watch?v=e6kVkzMaMyY 

Orchestra instrumental version: https://www.youtube.com/watch?v=17P0UycHUOg

OST part 1

Shinae An - Confusion https://www.youtube.com/watch?v=sxttqk6DXRY

OST part 2

LEE RAON -Next to you https://www.youtube.com/watch?v=hYesmHxooXE

OST part 3

Elaine - Stand by Me https://www.youtube.com/watch?v=5b3TbTa3xEE 

OST Part 5

O.WHEN - Think of Me https://www.youtube.com/watch?v=okCw07xVrMU

OST Part 7

Lee Seung Yoon - Last Story https://www.youtube.com/watch?v=WyogRTTds8c  

I guess this is the last one until the BGM/VA OST comes out. Nothing defeats Break Through yet. Awesome song. I hope it gets the recognition it deserves in its home country :)