Tracks Done:

Goodbye With A Smile by Alex Chu of Clazziquai.
Tears Are Falling by F.T Island.
One Minute One Second by Epik High. 
Never Knew I Needed You by Ne-yo.
I Hope Its You by Zia ft K.will.
It's Okay Even If It Hurts by Seohyun. (Kim Sooro OST)
Intoxication by Xiah, Junsu.
When The Door Closes by Sohn Dongwoon and Yoon Doojoon.
Heartbreaker by G-Dragon.
Only One by B1A4.
Can U Smile by Infinite.
Forgotten Season by Kim Jaejoong.
Like Being Hit By A Bullet by Baek Jiyoung.
You Wouldn't Answer My Calls by 2AM.
Here I Am by ZE:A.
Oh by Kyung of BlockB.
Angel by Teentop.
In Heaven by JYJ.
Mistake by SNSD.
I'm A Loner by C.N Blue.
Banmal Song by Yongseo Couple.
It Hurts by 2NE1.
Was I The Only One by Jordin Sparks.
 

Idols In Story:

Shim Changmin of DBSK.
Lee Hongki of F.T Island.
Nichkhun Horvejkul of 2PM.
Nam Woohyun of Infinite.
Yang Seungho of MBLAQ.
Sohn Dongwoon of BEAST.
Kim Jaejoong of DBSK. (X2)
Yoon Doojoon of BEAST.
G-dragon/Kwon Jiyong of BIGBANG.
Jung Jinyoung of B1A4.
Lee Sungyeol of Infinite.
Kim Heechul of Superjunior. (Doesn't anyone else miss this man? I was already craving for Dari to come back and off he goes as well. Sobs.)
Yong Junhyung of BEAST.
Park Hyungshik of ZE:A.
Kyung of BlockB.
Lee Chunji of Teentop.
Minwoo of ZE:A.
Sohn Dongwoon of BEAST.
Lee Sunyeol of Infinite.
Lee Taemin of SHINee.
L.Joe of Teentop.
Kim Kibum of Superjunior.