2PM will be making their comeback with their 4th regular album <GO CRAZY!> 2PM, who have announced their comeback on September 15th, have not only been taking part in promotions in Japan, after their album <GROWN> in May, 2013, but they have actively built upon their music development as individuals and artistic talents through drama, film and comedy etc. It’s been 1 year and 5 months coming back as a whole group. The title song "GO CRAZY!", having the same name as the album, was produced by 2PM’s member Jun. K. It is the first time ever where 2PM will be running their album and music activities with a member’s own music. First, the title song "GO CRAZY!", which is included in the regular album, is based on disco and house music, a level upgraded of excitement and fun from their previous album. Jun. K, who wrote the melody and lyrics, got inspiration from people frequently using the statement, “GO CRAZY!” when making this song. 2PM’s 4th regular album <GO CRAZY!> contains a total of 11 songs; including another song produced by Jun. K and 2 songs written and composed by Chansung. The album, itself is presented with high quality, with 2PM’s mature charms expressed in diverse styles. One of the songs included in the album, ‘Like tonight’, is a song where you can get a true taste of 2PM’s moderate but groovy voice. The restraint melody, urbaneness chord, analogue synthesizer and instruments were mixed with retro, urban and funkiness to paint the emotions of a man wanting to spend forever with his lover on a lovely night like this. 2PM’s member Chansung and song-writer Shim Eun Ji, together worked on the song ‘Boyfriend’. The song starts with a unique piano tune and monologue musical melody line. The song stands out because it is 2PM’s new attempt of a peculiar and dreamlike R&B song. ‘She’s ma girl’ is a song of someone feeling like the king of the world after falling in love. ‘Awesome’ is a song about being very surprised to have met a woman of great charm. ‘Pull&Pull’, is a song written upon the source of pushing and pulling in a relationship. ‘Goodbye Trip’ is specially expressed as a sad dance song filled with 90s pop, singing of a break-up. ‘Rain’ is a song reminiscing the emotions and sounds of 60s and 70s LP and lyrical sitar line, also having a memorable and unique warm feeling of R&B Ballad. Chansung took participation in writing the song ‘Mine’, a song expressing the confidence of a guy pleading the trust of the girl he likes. The Korean version of 2PM’s 4th Japanese single ‘Beautiful’, ‘Beautiful’ (Kor ver.)’. The Korean version of 2PM’s 2nd single ‘I’m your man’, ‘I’m your man (Kor ver.)’ are also included in the album.