KPOP 2nd generation · SM Entertainment
f(x)
エフエックス / 에프엑스
f(x) made the strangest records SM Entertainment released, and the albums have aged better than almost anything else from their years.
- 2009DebutSep 5, 2009
- 4Members
- 2thGeneration
- MeUFandom
Last updated:
01
In 30 seconds: f(x)
Victoria, Amber, Luna and Krystal worked with Sulli until 2015, and the run from LA chA TA through Pink Tape to 4 Walls keeps getting more assured.
Start here if you judge groups by albums rather than singles; this is the strongest case in second-generation pop.
02
Key facts
- Group name
- f(x)
- Reading / Hangul
- エフエックス / 에프엑스
- Company
- SM Entertainment
- Debut date
- September 5, 2009
- Days active
- 6,265 days (17 years, 1 month)
- Debut song
- LA chA TA
- Generation
- 2nd generation
- Fandom name
- MeU
03
Member guide
ビクトリア빅토리아 · VictoriaView in Japanese
Profile comparison
| Members | Birth date | Blood type | MBTI | Nationality | ||
|---|---|---|---|---|---|---|
| ビクトリア | 1987-02-02 | 39 | 168cm | A | Not disclosed | China |
| アンバー | 1992-09-18 | 34 | 165cm | B | Not disclosed | United States · Taiwan |
| ルナ | 1993-08-12 | 33 | 161cm | A | Not disclosed | South Korea |
| クリスタル | 1994-10-24 | 32 | 165cm | A | Not disclosed | United States · South Korea |
| ソルリ | 1994-03-29 | 32 | 172cm | O | Not disclosed | South Korea |
Ages are as of 2026-10-31.
Selected releases
04
Start here
Follow a few songs from the starting point to the group's current sound.
4 Walls / COWBOY
Electric Shock MVElectric Shock is the most addictive of the singles and the usual first listen.
Rum Pum Pum Pum MVRum Pum Pum Pum comes from Pink Tape and shows how odd the writing was willing to get.
4 Walls MV4 Walls is the most refined thing in the catalogue and the best argument for the whole project.05
From debut to now
- 2009A multinational lineup and an experimental pop feel introduced this new girl group from SM.
- 2010Nu ABO is the early signature song that shows the irregular hooks of f(x) most plainly.
- 2011The 1st Album and its repackage held experiment and catchiness together.
- 2012Electric Shock is the signature track easiest to recommend to anyone meeting f(x) for the first time.
- 2013Pink Tape is the record that raised the standing of f(x) at album level.
- 2014Red Light is dense in both sound and visuals, bridging into the later era.
- 20154 Walls leans toward house and is the representative entry point into late f(x).
- 2016All Mine, an official MV from the late period, carries the afterglow that follows 4 Walls.
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Achievements
Key milestones
Verified information
Verified English information is not yet available for this section.
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Official links
Official site
Official social accounts and platforms
Shopping guide
Verified English shopping links are not yet available.
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KPOP DISCOVER's f(x) note
f(x) turns on experimental electro pop and on being judged album by album. The SM Entertainment girl group debuted in 2009 with LA chA TA, and separating the line of Victoria, Amber, Luna and Krystal from the stretch when Sulli took part, from the beginning through 2015, makes both the release history and the present route easier to sort.
Entry points are LA chA TA, Nu ABO, Electric Shock, Rum Pum Pum Pum, Red Light and 4 Walls. Pink Tape and 4 Walls both hold up as albums, and watching the performance footage rather than only the music videos is what carries the forward-looking side of f(x) across.
The releases run from the 2009 debut to All Mine in 2016, with the era of Sulli's participation and the 4-member era kept apart in chronological order. In the order Nu ABO, Electric Shock, 4 Walls, you pass through the experimentation, the signature song and the album-level regard.
Editors' take Nu ABO / Electric Shock / 4 Walls — an SM 4-piece whose experimental electro pop and album-level regard come through in three songs.
Trivia worth knowing
Name
The name f(x) reads like mathematical function notation, which suits a group whose combinations produce different results.
Fandom
The fandom is called MeU, a short way of naming the bond between the act and the people following it.
Nationalities
Victoria, Amber and Krystal made the multinational line-up one of the defining features at debut.
Album
Pink Tape and 4 Walls repay listening as complete albums rather than title tracks with filler around them.
Line-up
Splitting the timeline into the years with Sulli and the four-member period keeps the videos and releases in order.
Related
Placed next to Girls' Generation, Red Velvet and aespa, the lineage of SM girl groups becomes legible.
13
Japan activity score
KPOP DISCOVER original metric
No. 203/ 241 groups
No. 203 of 241 groups with recorded activity in Japan (top 84%)
- 1Japanese releases
- 1Japan-related tracks
- 0Members from Japan
- 0Official Japanese accounts
The denominator is the 241 groups, out of 564 covered by KPOP DISCOVER, whose raw score reaches at least one point. The score adds 10 points per Japanese-market release, 3 per Japan-related track, 12 per member from Japan, and 8 per official Japanese account. Japanese-market releases carry the most weight because they are the most direct evidence of activity; related tracks add track-level detail; members from Japan stand for Japanese-language communication and continuity; official accounts stand for a permanent point of contact. The weights are an editorial judgement, not a statistical optimisation, and the ranking tracks release volume in Japan closely. Source: releases, tracks, members, and official links recorded by KPOP DISCOVER (updated 2026-10-24).
How this score is calculated →View in JapaneseFrequently asked questions
What defines f(x)?
Victoria, Amber, Luna and Krystal worked with Sulli until 2015, and the run from LA chA TA through Pink Tape to 4 Walls keeps getting more assured.
Why should a new listener start with f(x)?
Start here if you judge groups by albums rather than singles; this is the strongest case in second-generation pop.
Which songs should a new listener try first?
Start with Electric Shock, Rum Pum Pum Pum, 4 Walls, then continue to the official video index.