About Lee Seong-jong
Lee Seong-jong (Korean: 이성종; born September 3, 1993), commonly known as Seongjong (formerly Sungjong), is a South Korean singer. He is a vocalist of the South Korean boy band Infinite under Woollim Entertainment. He is also the vocalist of Infinite F. == Early life == Lee was born in Gwangju City, South Korea, on September 3, 1993. He moved to Andong when he was 9. He has a younger brother three years younger than him named Lee Seon-gyu. He graduated from Jeonju Arts High School on February 7, 2012, and was studying at Kongju University. == Career == === Infinite === Lee was first introduced as a vocalist of the boy band Infinite in 2010. His first appearance as a member was during Infinite's pre-debut reality show You Are My Oppa. The group officially debuted on June 9, 2010. === Infinite F === Lee was announced as a member of Infinite F during the One Great Step Returns encore concert, along with Sungyeol and L. There, they performed the song "My Heart is Beating".
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.