BTS, also known as the Bangtan Boys, is a seven-member South Korean boy band that began formation in 2010 and debuted in 2013 under Big Hit Entertainment. The septet, which is composed of RM, Jin, Suga, J-Hope, Jimin, V, and Jungkook, co-writes and co-produces much of the group's output. Originally a hip hop group, their musical style has evolved to include a wide range of genres. Their lyrics, often focused on personal and social commentary, touch on the themes of mental health, troubles of school-age youth, loss, the journey towards loving oneself, and individualism. Their work features references to literature and psychological concepts and includes an alternative universe storyline. The group has released several albums and performed on several world tours.