[3] He joined the band as a guitarist and backup vocalist[4] after former member Oh Won Bin left the group.

[5] Right after joining FT Island as Oh Won Bin's replacement, "I Believe Myself" became the first single with member Song Seung-Hyun's vocal.

In 2009 Song Seung-hyun appeared on SBS's variety show program Idol Maknae Rebellion ("아이돌 막내반란시대").

[6] He also did a cameo in Style [Ep6] (SBS, 2009)[7] In 2012 Song Seung-hyun made his musical debut on 'Jack the Ripper' as Daniel.

[12] In February 2024, Song announced his retirement from the entertainment industry and leave Korea to live a new life.