For brief history and notable artists, I'd like to recommend this blog post (really good):
50 Most Influential K-Pop Artists Series Index
This book has many interesting facts about Korean Cool:
The Birth of Korean Cool: How One Nation Is Conquering the World Through Pop Culture
I'm a Korean live in Seoul. I can't explain/describe properly (miserable ...
Based on Janice Lim's comment the YouTube video,
사랑은 언제나 오래 참고 （Love is Always Patient)
It's a Christian/gospel song (which supports the church scene in the video) based on 1 Corinthians 13:4-6.
Love is always patient; love is always kind; love is never envious or arrogant with pride.
Nor is she conceited, and she is never rude; she never thinks just of ...
Here it is!: It seems to be translated to 'Creating Love'. It seems to be a soundtrack for something in Korean, I assume from the TV show. I do not read nor speak Korean, so there is not much more information I could find outside of this:
Title: 사랑 만들기
Release date: 2010-04-21
It's not clear from your question which theme you are looking for, but what seems to be a complete soundtrack listing is in the Wikipedia article:
"Love Story" Kim Jang-woo Kim Ji-hyang
"A World That Is You" (그대라는 세상) Han Joo Lee Yoo-jin Yoon Mi-rae
"Lean on You" (너에게 기울어가) Kim Ji-hyang
"Shy Boy" (설레이는 소년처럼) Shin Hae-chul