Singers Lyn and Baek Ji Young have enjoyed unprecedented success as they sing the soundtracks for various TV dramas. Lyn sang "My Destiny" for SBS's hit drama "My Love From the Star" as well as "Back In Time" for MBC's 2012 hit drama "Moon Embracing the Sun". Baek Ji Young sang "Don't Forget" from KBS's "IRIS" as well as "That Man" from SBS's "Secret Garden". Their success is definitely something that other artists are also trying to mimic, so the question has to be asked - what brings an artist and an OST together?
Because OST's are made as an accessory to the drama, the music director assigned to the drama makes all the executive decisions. They are influenced by the suggestions of the actors and actresses as well as the directors and producers of the drama. Most music directors go for the artists whose previous OST tracks were financially successful. There are currently only a handful of artists that fit into that category - Lee Seung Chul, Im Jae Bum, Baek Ji Young, Sung Shi Kyung, Lyn, and Kim Tae Woo.
From the singers' viewpoint, there really is nothing to lose in participating in the OST. If their song becomes popular, they can climb the online charts and have the attention of the fans in between albums. This is a good financial decision as well.
There is a reason that the previously mentioned artists are always making hit songs out of soundtracks. It is because they are meticulous in choosing which drama to participate in. They pre-read the scripts, talk to the producers, and try to get a general feel for the drama previous to singing for the drama.
For example, young people gravitate toward romantic comedies. Since the younger generations are the ones that buy the most soundtracks, the top stars may opt for the Wednesday or Thursday melodrama slots rather than the morning or weekend dramas, which are enjoyed by a much older generation. Older generations tend to shy away from purchasing anything online, which drives down album sales despite the success of the drama.
OST singers do not make any independent decisions about the music. This is because the music that is used in a drama is vastly different from K-Pop.
Lyn commented on this, saying, "Drama music is usually draggy. They usually lack the ups and downs of a typical K-Pop song, but simple melodies and the gentle rhythm work well together with the drama, especially if there is a conversation in between the characters. I actually think if the singer's voice becomes too prominent, it takes away from the scene."
There are also times when an artist brings a song into the OST. This usually happens when an artist is inspired to write a song for the drama or if they believe one of their songs might fit the work best. For example, Baek Ji Young gave her own song "That Man" that she was saving for her album to the drama "Secret Garden" because she felt that the song fit in with the drama perfectly.