Be Natural

"Be Natural" was originally recorded and released by S.E.S. in 2000, becoming a hit single from their fourth studio album A Letter From Greenland.[1] As part of promotions for SM Entertainment's pre-debut group SM Rookies, which three of the members were a part of, a performance video of "Be Natural" by member Irene and Seulgi (then-known as SR14G) was uploaded onto the label's YouTube channel on July 17, 2014, shortly before the video teaser for "Happiness" 10 days later.[2] The record used in the performance was also re-recorded.

The first teaser was released on October 6, 2014, showing all four girls in suits, hinting at a transition to a more mature concept from their first single, "Happiness".[3] More teasers were released before the group made their comeback stage on M! Countdown on October 9. S.M. Entertainment released the music video for the song on their official YouTube account hours later. The single, on the other hand, wasn't released digitally until October 13.

"Be Natural" is mainly an R&B song composed and arranged solely by songwriter Yoo Young-jin, with strong influence from soul and jazz elements. It also contained a rap verse, performed by Hyuggie in the original version and then-SR14B's Taeyong. For the re-recorded version by Red Velvet, the arrangement and rap verse remained the same to the original version by S.E.S., composed in the key of B♭ minor with a tempo of 89 beat-per-minute.[4] Lyrically,

The music video shows the original choreography seen in the pre-debut performance of members Irene and Seulgi.

The music video was directed by SM performance director, Shim Jae-won, who also worked with renowned choreographer, Kyle Hanagami, for the choreography.[5] The original choreography of the music video was seen in the pre-debut performance of members Irene and Seulgi. The music video includes dynamic movements of camera on which was shot using one-take techniques.[6] It also featured then-SR14B member Taeyong performing the rap verse, instead of not including the rappers in the original video by S.E.S. in 2000.

Following the music video release, Red Velvet began the promotion for "Be Natural" on Mnet's M! Countdown on October 9, followed by performances on Music Bank, Show! Music Core, Inkigayo and Show Champion.[7][8] The girlgroup would then perform the song again as a dance section during their first concert Red Room in 2017, which also marked their first time performing it as a quintet since member Yeri joined the group shortly after its release in October 2014.