4minute --the cooler than cool K-pop group best known Stateside for the solo career of star member HyunA-- made an unexpected return today with a new song called Cold Rain--and it's a ballad!

The fivesome's signature has always been club-friendly electro tunes or genre-bending pop ditties from Korean hitmakers like Shinsadong Tiger and Brave Brothers, so Cold Rain marks the first time that they've ever tackled the ballad genre.

And surprisingly enough, it actually suits them quite well.

The melancholy production (courtesy of Son Young Jin and Jo Sung Ho, who recently produced Davichi's Sorry I'm Happy) is just as gorgeous as it is gloomy. The group also gets a real opportunity to showcase their singing for once, with each member having a uniquely different style, from spine-tingling high notes to gentle rapping.

For those of you that aren't feeling the whole ballad direction, don't worry: 4minute will be back early next month with a proper pop single.

Check out Cold Rain below.

SM Entertainment's new girl group Red Velvet are already off to a huge start, with their debut single "Happiness" debuting at an impressive No. 9 on this week's Gaon chart.

To put this into perspective, SM Entertainment's last new group, EXO, only reached No. 86 with their first single, "History." Outside of SM, Red Velvet is actually the highest-charting rookie group of 2014 so far.

Elsewhere on the chart, SISTAR's "Touch My Body" slips to second place after a 2-week reign at the top to make way for San E's "Body Language," which rockets in at No. 1.

Block B's "Her" is down to No. 3, followed by HyunA's "Red" at No. 4, and Girl's Day's "Darling" which rounds out the top five at No. 5.

Park Boram debuts at No. 11 with "Beautiful," but she should rise even higher next week judging by her current performance on real-time digital charts like Melon.

On the other hand, Ladies' Code's "Kiss Kiss" debuts at No. 59, but unlike Park Boram's song, it probably won't climb any higher next week; as of this posting, it's already almost out of Melon's top 100. This will actually mark the first real flop for the group, who have been on a winning streak since launching last year with "Bad Girl."

A few spots down is Brown Eyed Girls' "Hush" at No. 62, followed by Hwayobi's "Closer" at No. 66.

Check out this week's new K-pop hits, below.

No. 1. San E - Body Language

No. 9. Red Velvet - Happiness

No. 11. Park Boram - Beautiful

No. 59. Ladies' Code - Kiss Kiss

No. 62. Brown Eyed Girls - Hush

SISTAR have hung onto the No. 1 spot for a second week with their latest single, "Touch Your Body." The song is still sitting comfortably at No. 1 on the Melon digital music chart, too, so we could potentially see the quartet spend a third week at the top of the Gaon chart. If that happens, then "Touch My Body" will become the longest-running No. 1 in almost two years.

Overall, "Touch My Body" is SISTAR's fifth No. 1 as a full group, and their 11th if you include their subunit, solos, and collaborations. It's this kind of success that's helped them become Korea's second biggest girl group -- after Girls' Generation, of course.

In second place is Block B's "Her," which climbs one spot to No. 2 this week. It's the highest-charting song of Block B's career, and its success is pretty impressive by boy band standards. Male artists generally tend to fare better with physical album sales, while the digital market is dominated by girl groups and OST ballads.

HyunA's racy "Red" debuts at a solid No. 3, matching the position of her signature hit, "Bubble Pop!," but failing to reach the No. 1 and No. 2 peak of both "Ice Cream" and "Change."

INFINITE's flawless "Back" slips two spots to No. 4, followed by Girl's Day's "Darling" at No. 5.

JYJ's new single "Back Seat" debuts at No. 6, while all the songs from their latest album, Just Us, are scattered throughout the rest of the top 100.

Further down, Wonder Girls' Yenny, who now goes by the bizarre and confusing name of HA:TFELT, enters at a respectable No. 16 with her first solo single, "Ain't Nobody." The position pales in comparison to her ex-bandmate Sunmi, but is relatively decent by solo female standards, putting her on par with T-ara's Jiyeon and Hyomin.

The new HIGH4 single with Lim Kim, "A Little Close," enters at No. 29, while Sunny Hill's "Once In Summer" arrives at No. 47 to become their lowest-charting single ever.

Speaking of flops, BESTie's "Hot Baby" debuts at a disappointing No. 53. Although this matches "Thank U Very Much" as their highest-charting single, it's still a let down for the group, who should be doing much better at this point.

Check out this week's key K-pop hits, below.

No. 1. SISTAR - Touch My Body

No. 3. HyunA - Red

No. 4. INFINITE - Back

No. 6. JYJ - Back Seat

No. 16. HA:TFELT - Ain't Nobody

No. 53. BESTie - Hot Baby

HyunA proved that she knew how to shake her booty like a pro with her 2011 viral hit "Bubble Pop!," but the K-pop princess has taken her twerking to a whole new level for her new single "Red."

The 22-year-old performed the bonkers electro-hop track on Korean music program Music Bank last night, and to say that it she shut it down would be a major understatement. She popped it, dropped it, twerked it, shook it, dipped it low, picked it up slow, and even hit the splits in high heels.

HyunA may not have as much junk in the trunk as Beyonce and JLo, but she showed that it's not the size that counts, but what you do with it that's most important.

Outside of PSY, there aren't too many K-pop hits that have been able to capture people's attention outside of the usual community of K-pop fans. HyunA's "Bubble Pop!" is one of the select few songs that did break out; it became a mini viral sensation after its release in 2011, racking up over 70 million views on Youtube and scoring HyunA press from Billboard, Spin, and Pitchfork -- at one point, there was even talk of her making an American advancement off of the popularity of the song.

Unfortunately, HyunA never did quite make it the States, but the impact of "Bubble Pop!" can still be felt today.

Sexy quartet SISTAR --who are currently the second biggest girl group in Korea after the almighty Girls' Generation-- released their new single "Touch My Body" this week, and it looks and sounds a lot like HyunA's "Bubble Pop!."

The two songs share some noticeable similarities, but not to the point where you could call it plagiarism or recycling. "Touch My Body" is more like the turnt remix to "Bubble Pop!"; it's bigger, louder, and sexier. The most noticeable difference between the two is the heavy sax used in "Touch My Body", which routinely blasts in and out of the song until the bridge, where it gets the kind of repetitive solo that Alexandra Stan would kill for.

Throw in some hot pants, booty shaking, and cartoon-y effects in the music video, and you've got the "Bubble Pop!" of 2014.

Funnily enough, "Bubble Pop!" was actually directly 'inspired' by Britney Spears' Femme Fatale cut, "How I Roll," so I guess you can say that both SISTAR and HyunA are really just poppin' in the house that Britney built.

Earlier this week, K-pop princess HyunA released a teaser photo for her new album that showed her posing next to some shirtless hunks in giant monkey masks. Now, in the new music video teaser for her upcoming single "RED," there's some serious role reversal going on; HyunA's now the topless one, posing with an actual real monkey clinging to her bare chest.

I'm sure I speak for everyone when I say: WHAT THE HELL?!