1. The theme song "The Hedgehog Effect" is a song composed by JJ Lin, lyrics by Jiang Linfeng, and sung by Mo Xi'er. The song is included in the album "Youth Lost Paradise Movie Soundtrack" and was released on 2011-11-11.

2. The interlude "On Stage" is a song composed by Liu Jia, lyrics written by Da Liu, and sung by Smile Queen. The song is included in the album "Youth Lost Paradise Movie Soundtrack" and was released on 2011-11-11.

3. The interlude "I Need Love" is a song composed by Anonymous, written by Anonymous, and sung by Sam Phillips. The song is included in the album "Youth Lost Paradise Movie Soundtrack" and was released on 2011-11-11.

4. The interlude "Your Love Is Too Arrogant" is a song composed by Anonymous, written by Anonymous, and sung by Youyi Tan. This song is included in the album "Youth Lost Paradise Movie Soundtrack" and was released on 2011-11-11.

5. The interlude "Flying in the Clouds" is a song composed by koshin, written by Jiang Linfeng, and sung by Mo Xier. This song is included in the album "Youth Lost Paradise Movie Soundtrack" and was released on 2011-11-11.

6. The interlude "Double Face" is a song composed by Zhang Kailin, lyrics written by Li Sanmu, and sung by Xie Ronger. This song is included in the album "Youth Lost Paradise Movie Soundtrack" and was released on 2011-11-11.