During the showcase for her mini album 'Warning', Sunmi talked about "Siren", which she wrote the lyrics for and FRANTS composed. She revealed, "About two or three years ago when Wonder Girls was promoting as a band, this song was being considered as a title track alongside 'Why So Lonely'. It was determined the song wouldn't sound as great if arranged for a band, so I've been keeping it in mind and hoping there would be a time for me to showcase it."
She continued, "Sirens are used as warnings, but I was also inspired by sirens of mythology. They are known as beautiful but frightening beings that lure sailors in with their beautiful voices and drag them to the bottom of the ocean. The mermaids in 'Pirates of the Caribbean: On Stranger Tides' were also sirens. I think I'll be able to take that unique concept and express it well. The reason sirens stuck out to me is that they're what are used in the most dangerous of situations, and the origin of the word 'Siren' is the figure of the mermaid. The song itself has an ambiguous meaning, so I wanted to use the word."
Are you surprised to hear Sunmi's "Siren" was originally meant to be a Wonder Girls song?