4 Walls
Studio Album by f(x)
Released: October 27, 2015
Recorded: 2015 at S.M. Studios, Seoul
Genre: Electronic, Dance-pop, Synthpop, K-pop
Language: Korean
Length: 35:18
Label: S.M. Entertainment, KT Music
Producer: Lee Soo-Man
White Version
f(x) chronology
Red Light

4 Walls is the fourth studio album by multi-national girl group, f(x), and the first as four members due to the departure of Sulli on August 7, 2015.[1][2]

Currently, there are four songs from the album included in Superstar SMTOWN.


"Cash Me Out" was a track initially recorded by Swedish singer Zara Larsson and appeared on her 2013 extended play Allow Me To Reintroduce Myself. SM Entertainment purchased the rights to the song sometime prior to the release of Pink Tape, though the song was ultimately not included on the album. It was speculated that the song was initially chosen as the album's title track prior to "Rum Pum Pum Pum" being chosen, as scenes of the girls rehearsing choreography to Larsson's version can be seen on 2013's Go! f(x).[3]

It was also speculated that "Cash Me Out" was intended to be the lead single from a rumored Red Light repackage that was scrapped due to Sulli's abrupt hiatus, in part because during the 2014 SMTown tour, Luna was seen performing with "Cash Me Out" armbands.[4] After the release of 4 Walls, more clips of the group's dance practice from 2013 was leaked on Twitter.[5]

"When I'm Alone" was initially a song written and co-composed by Carly Rae Jepsen during sessions for her second studio album E•MO•TION (but was ultimately left off the final tracklist) and later was purchased by SM Entertainment.[6]


Bold track titles means the track is currently playable.

  1. "4 Walls"
  2. "Glitter"
  3. "Deja Vu"
  4. "X"
  5. "Rude Love"
  6. "Diamond"
  7. "Traveler" (feat. ZICO of Block B)
  8. "Papi"
  9. "Cash Me Out"
  10. "When I'm Alone"

Release and Reception

The album received both commercial and critical success domestically and internationally. In Korea, the album sold 66,000 copies in its first week of release,[7] breaking two records. f(x) became the female group with the highest first week sales in 2015 (beating the record previously held by Taeyeon's I, which sold 54,600+ copies in its first week of release),[8] and placed second on the list of most first week sales of all time for a girl group (beating the record previously held by Girls' Generation's Oh! which sold 65,500+ copies in its first week).[9]

Internationally, the album also debuted at the number one spot on the Billboard World Album Charts[10] and became critically acclaimed on Pitchfork,[11] making them the only Kpop group apart from 2NE1 to be featured on the website.