Six months after the release of their funky, innovative album The Red, Red Velvet returns to the K-pop scene a little softer. The girl group that garnered a lot of attention last year for their spunky singles “Dumb Dumb” and “Ice Cream Cake” are back to showcase a more melancholic image on their new track “One Of These Nights.”

“One Of These Nights,” or “Seventh Day of the Seventh Month” as its known in South Korean, is an R&B inspired track full of longing. The song takes its themes from the Korean folktale of Jiknyeo and Gyeonwu, lovers separated all but one day each year -- the seventh day of the seventh month of the lunar calendar. The mournful tone of Red Velvet’s voices are clear throughout the rising ballad, driven by orchestral accompaniment and a guiding bass.

The dreamy single explores regret following a breakup and is one of the group’s most expressive vocal performances to date, with Wendy’s belting taking a focal point in the song’s arrangement to match the others’ lighter harmonies. “One Of These Nights” is different from their most recent hits: As good as those songs were, this isn't a bad thing, since it's nice to see Red Velvet turn back to their velvety side.

“One Of These Nights” continues the path of Red Velvet’s early songs “Be Natural” and “Automatic,” emphasizing a classier image that counters the brighter concepts that Red Velvet has captured in their more recent upbeat “red” singles. But “One Of These Nights” is just as compositionally stimulating as something like “Ice Cream Cake.” Soaring piano, strings, and tinkling chimes sit beneath Red Velvet’s voices to build the song up to a dramatic finale -- it's not as bouncy as “Dumb Dumb,” but no less captivating.

Red Velvet’s latest EP, The Velvet, features not one but four versions of “One Of These Nights,” including the original composition, the De-Capo version, the so-called Joe Millionaire style, and a piano rendition to better showcase the wide-array of sounds explored by the song.

Check it out above.