As anyone familiar with Hark Joon Lee's eye-opening 2013 documentary "Nine Muses Of Star Empire" knows, the K-pop girl group has had their share of ups and downs.

Though despite having six band members exit sine the group's formation in 2010, it would appear that Nine Muses may be finally ready to set aside the dramas of the past and get down to producing quality music.

Whoever's decision it was, the choice to have the group team up with veteran Hallyu hitmaker Brave Brother was a masterstroke.

Where past producers have ended up with singles where the members of Nine Muses sounded stiff, self-conscious, overly showy or understated to the point of anemia, on "Sleepless Night," released Tuesday as part of the group's "Lost" EP, Brothers lands the singers right in a sweet spot embodying both the detached cool of Lim Kim or IU with the powerful precision of K-pop girl group icons like Wonder Girls or 4Minute.

Beneath it all, Brave Brothers once again reinvents his own sound, producing a sleek combination of classic pop writing with the soulful shuffle of modern dance innovators like Santigold or Raphael Saadiq. While he is sometimes criticized for repeating himself (a fairly ridiculous charge considering his track record producing a dizzying array of hits for many of South Korea's biggest acts from Big Bang to SISTAR), there is no denying that Brothers has dialed in a genre of music that is difficult to define on "Sleepless Night."

Nine Muses may not have experienced the commercial success of many of their contemporaries nor have the kind of squeaky-clean track record or simple bio that many Hallyu fans seem to look for.

However, with "Sleepless Night" they have just produced their first great song. For any true music fan, that should basically be all that matters.

Watch the music video for the Brave Brothers-produced single "Sleepless Night" from K-pop girl group Nine Muses RIGHT HERE