Two of K-pop's veteran girl groups made comebacks in recent months - albeit with fewer members.
Both acts mark their eighth year in show business - a feat in the capricious K-pop world.
Girls' Generation released their fifth album Lion Heart as an octet, sans ex-member Jessica Jung, who is chasing her fashion ambitions.
After a three-year hiatus and a refreshed line-up, Wonder Girls released their third album, aptly titled Reboot.
The group's line-up has undergone multiple changes.
Member Sohee did not renew her contract in 2013 and later left to concentrate on her acting career.
The group also lost their leader, Sunye, who got married in 2013 and is now a mother. She has a two-year-old daughter and another baby is on the way.
Now a quartet, the Wonder Girls welcomes former member Sunmi, who left in 2010. For their anticipated return, they have produced a cohesive 1980s sound, from synth-pop infused Baby Don't Play to old-school ballad Remember.
The members had a hand in either the music or lyrics in 11 of the 12 tracks.
I'm bopping along to the hip-hop ditty Back with funky cowbell grooves complementing the rapping of Yubin and Hyelim - although rapping the word "back" over and over gets a tad repetitive.
Tapping on the past for inspiration comes as no surprise as the girls have a track record of trotting out retro tunes.
Think of their worldwide smash hit Nobody (2008), a 1960s Motown anthem.
Interestingly, Girls' Generation have also incorporated retro elements on their title track Lion Heart and in their members' get-up for the accompanying music video.
Crooning about taming a two-timing (no, make that eight-timing) cheater, Lion Heart is modern-day pop peppered with a lilting vintage melody.
That's where the nostalgia ends. The token retro tune is set alone in a a mish-mash of 12 tracks of varying genres.
There's high-octane club banger You Think and breezy, summery tune Party.
The garden-variety songs are decent, but hardly earworm material like their catchy hits such as Genie (2010) and Hoot (2010).
Out with the old, in with the new? Nah, I'm sticking with the addictive oldies for now.