Moon Byul-yi (Korean: 문별이, born December 22, 1992), known professionally as Moonbyul (문별; stylized as Moon Byul), is a South Korean rapper, singer and songwriter under RBW Entertainment. She is a member of the South Korean girl group Mamamoo and its sub-unit Mamamoo+.
Moonbyul made her solo debut in May 2018 with the digital single Selfish. According to the Korea Music Copyright Association, she has songwriting credits on over 100 songs.
Moon Byul-yi was born on December 22, 1992, in Bucheon, South Korea. In 2011, she was accepted into the Paekche Institute of the Arts, where she studied media music and vocals.
During her middle school years, she became interested in singing after watching TVXQ's performance of "Rising Sun". She decided to pursue singing after receiving positive feedback during a school performance. She also cited Girls' Generation and their leader Taeyeon as early influences on her career aspirations, and attended SM Entertainment's academy in an attempt to follow in her footsteps. She graduated from Wonmi High School, and later from the Paekche Institute of the Arts majoring in media, music and vocals.
Moonbyul's stage name combines her family name "Moon" with her given name "Byul-yi". Her given name "Byul-yi" means star in Korean. According to Moonbyul, she has stated that her father chose the name "Byul-yi", meaning star, inspired by the night of her birth.
She uses the alias "Moonstar" as her rap name, which directly translates the meaning of her Korean name into English. Since her debut, she has incorporated the alias "Moonstar" in several of her lyrics, including in collaborations with other artists. The motifs of the moon and stars are often associated with her as well.
Moonbyul debuted as the main rapper and performer of Mamamoo on June 18, 2014, with the single "Mr.Ambiguous."The group became known for their vocal-centered musical style, according to Korean media outlets.
She joined her label RBW in 2011. Despite originally passing her audition as a vocalist and training as one, it was suggested to her by their record producer that she switch to becoming a rapper, as the group needed a rapper. Although she was rather unfamiliar with the genre and was only informed six months prior, she debuted with Mamamoo on June 19, 2014. According to the group's WAW documentary, Moonbyul also specialized in freestyle dance and hip-hop, and would show up to monthly evaluations with self-made routines she choreographed herself.
Moonbyul debuted as a member of the girl group Mamamoo on June 19, 2014, with the release of their first extended play (EP) Hello. As one of the members in charge of performance, she contributed to the choreography of the group's debut track, the lead single "Mr. Ambiguous".
Since the release of their second extended play Piano Man in November 2014, Moonbyul has co-written many of the group's lead singles, including the entirety of her own raps.
In November 2016, Mamamoo performed at the 37th annual Blue Dragon Film Awards, one of the most prestigious film awards in South Korean entertainment industry. They put a creative twist on their song "Decalcomanie" by including adlibs that referenced famous quotes and well-known lines from popular movies that year. In particular, Moonbyul's line "Jung Woo-sung, if I drink this in one shot, will you go out with me?", the moment received attention online and was widely shared on social media, contributing to the song's chart performance, along with his reaction that was captured on screen. The moment went viral in South Korea, garnering 1.5 million views within a day. The group and their song "Decalcomanie" gained a surge in popularity and rose to the top of real-time music charts, becoming a hit domestically.
In June 2017, Moonbyul released her first solo track, "Love & Hate", as part of Mamamoo's fifth EP, Purple. She wrote the song based on her own past relationship, conveying the heartbreak of feeling alone even while the other person was there. Her interpretation of the bittersweetness of first love, is reflected in her dancing in the performance video as well.
In May 2018, Moonbyul made her solo debut with the digital single "Selfish," featuring Seulgi of Red Velvet.
She released her first EP, Dark Side of the Moon, on February 14, 2020. Rolling Stone described the album as "surprisingly expansive in the genres it explores", experimenting with a range of genres including jazz, blues, ballads and hip-hop, while the lead single "Eclipse" is described as a "powerful blend of rock, synth and trap". Billboard commended the release for continuing Mamamoo's legacy of relaying different ideas of feminine strength through their music, adding praise to Moonbyul for being "Billboard noted her use of diverse genres and performance styles". Upon release, the album charted at number one on the iTunes Top Album Chart in four countries, and ranked within the Top 5 in ten regions worldwide. Its lead single "Eclipse" also peaked at number fourteen on Billboard World Digital Song Sales chart for the week of February 14, 2020. Dark Side of the Moon sold 66,000 copies in the first week of its release alone and the album reportedly sold 66,000 copies in its first week, placing high on the Gaon Chart.
2020–2021: Venturing beyond music and successful hosting debut
In July 2020, Moonbyul was appointed as a host for the weekly radio program Avengirls on Naver NOW. Upon garnering high broadcast ratings, she launched Studio Moon Night, her own flagship talk show, on February 15, 2021. With this live broadcast program that aired thrice weekly with new guests appearing each episode, she became the first Mamamoo member to venture into hosting and having a program named after her. She also composed and wrote the theme song for the show herself.
Studio Moon Night was renewed for a second season in March 2022 after marking its first anniversary of being on air. In May of the same year, Moonbyul was awarded at 2022 Korea Brand Customer Loyalty Index for her work as a host in the live broadcasting category. The Brand Customer Loyalty Awards is held annually by the Korean Consumers Council to recognize the brands and personalities that have the most influence on popular culture and society, as determined through consumer research in association with the U.S. consulting firm Brand Keys.
In October 2021, she joined the cast of SBS entertainment program Kick a Goal. Moonbyul scored her first ever goal on the August 24th, 2022 episode to help her team FC Top Girl advance to the Super League, which recorded the high viewership ratings of 9.6% per minute.