User:ILuvSunshine/sandbox/f(x) (band) cleanup

Original Soundtrack
In late 2009, Luna and Krystal contributed to the soundtrack of television series Invincible Lee Pyung Kang with a duet, "Hard but Easy".

In early 2010, Krystal, Luna and Amber also recorded the song "Spread Its Wings" for the soundtrack of the KBS's drama, God of Study. Krystal and Luna recorded a duet song for the KBS's drama Cinderella's Sister original soundtrack, called "Calling Out".

In late 2010, Luna released a single "Beautiful Day", as part of the official soundtrack of the KBS drama 'Please Marry Me'. On December 23, 2010, a duet collaboration between Luna and Super Junior's Yesung was released, titled “And I Love You“, for the second original soundtrack of KBS's President.

Television and Acting careers
Krystal appeared on a daily Korean sitcom called "More Charming By The Day" which started from March 22, 2010 to November 2, 2010. The sitcom has total of 138 episodes but Krystal appeared from the 60th episode.

On April 2, 2010, Y-Star started airing first variety show of the group, Hello f(x). The program consisted of four episodes which showed close coverage on their preparations for the first mini-album, Nu ABO.

On October 2, 2010, their second reality show, Koala, started airing on MBC's Every1. The show featured the group's background life during the SMTown Live '10 World Tour.

From May 2010, F(x) members started to appear in variety show on regular basis. Victoria was casted in We Got Married to become a couple with Nichkhun from 2PM. They have been on the show since. She was also casted as regular member of Invincible Youth, and appeared in the show until it ended in December 2010. Luna appeared in Star King and became regular member of the show. She went on to win "New Star" (신인상) award in 2010 SBS Entertainment Award (2010 연예대상). Sulli was casted as the co-host of Inkigayo (인기가요) along with Jo Kwon from 2AM and Jung Yong Hwa of C.N.Blue. She is still hosting the show with Jo Kwon, along with new co-hosts IU and Lee Gi Kwang

In late 2010, members Victoria, Sulli and Krystal became model endorsers for the clothing brand, Calvin Klein's X Jeans. A music video for the song, "Beautiful Day", was released in December 2010 to endorse the brand. The group also endorsed another clothing brand, K-Swiss, for their 2010 winter collection.

In addition to those endorsements, Victoria also was featured in Kangta's music video of his song 爱，频率 ("Love，Frequency"/"Breaka Shaka").

From May 2011 through August 2011, Krystal appeared as a contestant on Kim Yuna's celebrity ice skating show, "Kim Yuna's Kiss and Cry." After consistently scoring near the top of the competition, Krystal and her partner Lee Don Hun won the show with their flawless performance of "Carmen." Krystal and Lee Don Hun were later invited to participate in "Kim Yuna's Ice Show--All That Skate Summer 2011" on August 14 and 15.

Towards the end of the year, f(x) members pursued individual acting activities. On September 19, 2011, MBC aired the first episode of "High Kick 3," a daily sitcom show in which Krystal starred as one of the lead roles. In October, Amber was cast as a member of the second season of Invincible Youth. In November, Victoria starred alongside Super Junior's Kyuhyun in TRAX's music video for the song "Blind". In December, CSTV began airing the weekend drama "Saving Mrs. Go Bong Shil", which features Luna in the role of Seo In Young.

On December 31st, Victoria together with her We Got Married partner 2PM Nichkhun MC-ed the 2011 MBC Gayo Dajaejun Festival.

In January 2012, f(x) endorse 'Chicken Mania’ for the third year.

Overseas
In June 2010, Amber rapped in Korean and English for Taiwanese Mandopop artist Danson Tang on track, "I'm Back" from his third album The First Second.

In January 2012, Victoria starting filming When Love Walked In a Taiwanese drama.