f(x) finally return as 4-member group with Victoria, Amber, Luna & Krystal on this October!

On October 19th, f(x) first drop a hint about their upcoming comeback '4 Walls' with a picture and initials of each members on it through their official instagram account (@fx_4walls). Following the next day, on October 20th they drop another hint about where '4 Walls' exhibit will be held and what time.

After a long wait, finally on October 22nd at midnight KST, f(x) drop first teaser images and exhibit video of Victoria through official website (fx.smtown.com ). An hour before Victoria's teasers released, f(x) also updated their instagram with picture 'Notice'.

On October 22nd, SM released pictures from f(x) exhibit in Itaewon, Seoul containing '4 Walls' tracklist with title track '4 Walls'. The 4 album contains 10 song, '4 Walls', 'Glitter', 'Deja Vu', 'X'. 'Rude Love', 'Diamond', 'Traveler', 'Papi', 'Cash Me Out', and 'When I'm Alone'. At the midnight KST (10/23) Luna is the next member who revealed her teasers after Victoria.

f(x) title track '4 Walls' is song with dreamlike atmosphere and sophisticated with deep house EDM genre. 'Glitter' is a synthpop song, 'Deja Vu' is an EDM song about the first time to feel deja vu, 'X' is a synthpop song about the thrilled when expressing a people to the one you love, 'Rude Love' is a song with refreshing sound of house music and fun to listen.

In addition, Block B's Zico participated in rap featuring on 'Traveler', 'When I'm Alone' is a dreamlike song composed by Carly Rae Jepsen and Mono Tree, 'Diamond' is an EDM track with hip hop rhythm, 'Papi' is a Latin EDM song composed by Kenzie and London Noise, and last 'Cash Me Out' is an electronic pop dance track about pure love.

The third member who revealed her teaser is Krystal and it become more special because its also her 22nd birthday. f(x) uploaded Krystal's exhibit video on instagram and put 'Happy Birthday Krystal' on it. Finally the last member who revealed her teaser is Amber. The teasers has been released on October 25th at midnight KST. On October 26th f(x) released group teaser and music video teaser for '4 Walls' at midnight KST.

f(x) '[4 Walls] An Exhibit' will be held from October 21st to 26th at 8PM-0AM KST in Itaewon, Seoul. Meanwhile, f(x) 4th album '4 Walls' and music video will be released on October 27th at midnight KST. f(x) first V app live broadcast '4 Walls LIVE with Krystal' will be broadcast through SMTOWN's channel at 11PM KST. Krystal will share about f(x) new album before the release of '4 Walls' music video at midnight KST.

On the other hand, f(x) first comeback stage will be on Mnet M! Countdown next week on October 29th.

See more photos below!