It’s said that red velvet has an incredibly complex flavor. The unique taste comes from its duality, blending both sweetness and acidity to taste. This isn’t exactly a combination you’d expect, but that’s why it’s a confection unlike any other.

The same could be said about Red Velvet. This five-member girl group reached the upper echelon of the K-pop scene with a split concept: they meld the vibrant pep of their “red” side with the smooth R&B of their “velvet” side. The rapid pace of the industry sometimes means that it can feel jarring when groups change concepts. But reverse charms form the basis of Red Velvet’s group identity.

K-pop is known for artists rapidly shapeshifting between concepts, but Red Velvet takes that to another level. They can be anything they want: girl scouts, murderous vixens, eccentric carnies, aesthetic baddies, or B-movie heroines. Sometimes you gotta be bold, and this quintet is constantly pushing themselves into new territory, taking conceptual risks while maximizing the outsize talent of their unit.

Red Velvet has racked up a sizable amount of achievements over the years. Nine of their albums have topped Korea’s Gaon charts, and they won best female artist at the 2017 Mnet Asian Music Awards. Earlier this year, the ladies embarked on their first headlining tour in the States, and they instantly sold out a Los Angeles date. They ended up collaborating with Ellie Goulding on a remix of her recent hit “Close to Me.” This past year, “Bad Boy” made them the first girl group to top Billboard’s 2018 list of the best K-pop songs.

Somehow, it’s been five years since Red Velvet made their debut with “Happiness” in 2014. So, Billboard decided to celebrate their anniversary by combing through their discography and ranking our favorite songs. Happy birthday, Red Velvet! We hope to see even more sides of you in the next five years.

25. "Attaboy" (Perfect Velvet, 2017)

One of the most brilliant aspects of Red Velvet's artistry -- which you'll inevitably find as you read through this list -- is their ability to turn the unconventional into the most addicting of pop songs. The chorus of this hidden gem incorporates a chant-like melody that strangely fits right into the blend of dark, trap production and encouraging lyrics. This experimentalism shows the group at their best and is just one reason why their full projects are worth diving into far past the lead single. -- JEFF BENJAMIN

24. "Sunny Side Up!” (‘The ReVe Festival’ Day 1, 2019)

On the savory end of Red Velvet’s food-related imagery, “Sunny Side Up!” follows a fragile relationship that could be over easily. This egg-cellent track is the thematic cousin to labelmate f(x)’s “Rum Pum Pum Pum” in the sense that both build romantic storylines around surreal metaphors. (Not to mention, they share the same lyricist: Jeon Gan Di.) Word play knows no language barrier as Wendy belts, “Don’t make my mind all scrambled up!” Atop a reggae beat, this slow simmer of a song is one of their slinkiest R&B-sides yet. -- CAITLIN KELLEY

23. “Aitai-tai” (#Cookie Jar, 2018)

The opening harmonies might've fooled you into thinking this track would be a mild, romantic ditty, but Red Velvet’s “Aitai-tai” (“Miss You, I Always”) is a fizzy energy drink of a track. Production team MonoTree goes full Yasutaka Nakata on the instrumental, while Red Velvet fill out the foreground with flirtatious verses and a chippy chorus that would fit right into a Vocaloid track. -- MONIQUE MELENDEZ

22. “SAPPY” (SAPPY, 2019)

Red Velvet is not the type to skimp on Japanese singles, and this electro-pop number stands out with its big brass and heart-thumping beat. The titular “SAPPY” boy is stuck in a love triangle, and Red Velvet wants him to make a decision. “Log out from daydreams,” they sing at the fickle dude. (Although, it might not help that the music video is an office-based fever dream in video game form.) This is the most changeable specimen in Red Velvet’s museum of boys, which ranges from the bad to the really bad. -- C.K.

21. "Red Dress" (The Red, 2015)

Duality is a key word when talking about Red Velvet's music, and "Red Dress" represents how the quintet can so easily pivot their mood and sound mid-song. This standout from The Red sees the group opening with peppy energy over a staccato-focused rhythm, before flipping the song into a lush bed of soft synths and warm harmonies on the chorus. Never one to keep things simple, both styles get mashed together for the final, cleverly chaotic chorus. -- J.B.

20. “Lucky Girl” (Russian Roulette, 2016)

The girls prove you only need five members to take on big band. “Lucky Girl” is an amalgamation of the sonic variation the group excels at, with a collage of textures that includes circus music, electronica, and the “womp womp womp” of a sad trombone. But at its core, the song is a testament to how their vocal harmonies are so strong, they can pull off a bit of doo wop. These aren’t your grandma’s “shooby doos.” -- C.K.

19. “Happiness” (Non-album single, 2014)

Starting off their career with bird caws and the shouts of “Happiness!” Red Velvet stormed onto the K-pop scene in 2014 with a bright and percussive dance track full of quirky tonal jumps. Swerving this way and that while exploring the then-quartet’s colors -- including playful tag-teams from the girls’ powerful solos -- the song was a vibrant, addicting display of potential from the new act and set the foreground for their entire career. -- TAMAR HERMAN

18. “Ice Cream Cake” (Ice Cream Cake, 2015)

As the first single to feature its completed lineup, this is perhaps Red Velvet’s most off-kilter song. The track is led by a haunting, tinny beat and airy “la-la-la”s -- a running theme in Red Velvet’s singles. When it shifts gears, it explodes into hyperactive synth-pop, overflowing with charismatic deliveries from the members. A song that demands repeated listens, “Ice Cream Cake” was Red Velvet’s first true commercial success for obvious reasons. -- T.H.

17. "Light Me Up" (The Velvet, 2016)

With so many of today's pop stars looking to tap into the R&B market, they'd be wise to see how the RV girls navigate the space. The act boasts tons of tracks that would make any R&B-pop star's mouth water with "Light Me Up" representing one of their best. A soulful beat mixed with a gummy chorus and just a wink of sensuality displays how effortlessly the group can slip into, and conquer, velvety R&B. -- J.B.

16. “Russian Roulette” (Russian Roulette, 2016)

This upbeat track is the perfect distillation of the tonal dissonance at the heart of Red Velvet’s work. Who else could call themselves “your sweet Russian roulette?” But you have to watch the music video to get the full experience. The candy-coated visual could be mistaken for a Wes Anderson film if the girls weren’t on a deadpan murder spree. Sometimes saccharine and morbid go hand in hand. -- C.K.

15. “Time Slip” (The Red, 2015)

On its surface, Red Velvet’s “Time Slip” is the more restrained little sister of Charli XCX and Iggy Azalea’s “Fancy.” But take a closer listen and you'll hear what makes this one of Red Velvet’s standout B-sides. There’s the stabby, impossible-to-ignore synths, the tempo shifts that keep you on your toes, and the push-and-pull between the sassy talk-rapping and the softer, dreamlike chorus that embodies the lyrical haze between sleep and consciousness. -- M.M.

14. “You Better Know” (The Red Summer, 2017)

“You Better Know” is prime “crying in the club” fodder, doubling as a source of comfort and a dance track. This foray into EDM includes uplifting lines like, “There’s a world that’s been waiting for you as you are.” The song weaves through buildups and breakdowns, as the hushed verses explode into the synth-laden chorus. That dynamism paid off for the group: the song became one of their most commercially successful B-sides, reaching No. 14 on Korea’s Gaon chart. -- C.K.

13. “Cool World” (The Red, 2015)

The Red album closer “Cool World” opens with a loop pulled from Rob Base and DJ E-Z Rock’s “It Takes Two” that gives way to a synth-laden self-love anthem. “Being more different is what makes you special,” Seulgi croons on the most unabashedly uplifting song in Red Velvet’s arsenal. The song’s strength lies in its self-assured lyrics and the quintet’s vocal performances that communicate its message across linguistic barriers, with equal doses of tender vulnerability and reassurance that this world is so much cooler with you in it. -- M.M.

12. “Blue Lemonade” (Summer Magic, 2018)

From its first crooning bars until its finale, “Blue Lemonade” serves up a mellow yet effervescent blend of Red Velvet’s “red” and “velvet” sides, coming off as a electro-pop-meets-R&B track. It thrives on the expressive vocals of the group’s members, a snapping beat, and eccentric digital whirrs. There’s a sense of euphoric warmth throughout the song, redefining the feelings associated with the seasonal drink in the most refreshing of ways. -- T.H.

11. “I Just” (Perfect Velvet, 2017)

Perfect Velvet deep cut “I Just” is the most unconventional addition to the group’s “velvet” discography. With the help of producer Hitchhiker, the quintet trade in their quintessential “velvet” R&B motifs for a downtempo future bass instrumental, staccato chanting, full stops, and intriguing vocal slides. Backed by a floor-shaking soundscape, its quirks come together to build an evocative atmosphere that can’t be found on any other Red Velvet track. -- M.M.

10. "Some Love" (Russian Roulette, 2016)

Despite the Russian Roulette EP being released in early fall of 2016, Red Velvet easily had a contender for a song of the summer with album cut "Some Love." The on-trend tropical-house production mixed with the girls' bubbly vocals and shimmering pop beats made for a perfect, pool-party-ready jam. Simply, a feel-good summer track only elevated by a group whose personalities come shining through on record. -- J.B.

9. "Automatic" (Ice Cream Cake, 2015)

The dual concepts behind Red Velvet were fully seen in the two releases for the group's Ice Cream Cake album. While the album's sweet title track showcased the group's "red" side in all its bubbly glory, the "velvet" single "Automatic" stands as one of their smoothest cuts to date. Simple percussion lets the ladies' knack for silky harmonies shine in what's proven to be a key cornerstone of their sound. Throw in the complex, highly coordinated choreography shown in the music video, and Red Velvet quickly established themselves as a girl group beyond their years with this release. -- J.B.

8. “Peek-A-Boo” (Perfect Velvet, 2017)

Red Velvet’s “Peek-A-Boo” may be named after a game typically played with babies, but there’s nothing childlike about this 2017 song with its layered vocals and brassy melodies. Kicking off with pitchy synths and an idiosyncratic beat, it weaves in and out of different tonal shifts to show off the act’s diverse vocal colors, but always returns to the coy “peek-a-peek-a-boo” of the chorus. It was accompanied by a chilling music video that posed the women as a cool-gazed coven who murder food delivery guys. Dark and impactful, it served as the perfect backdrop to the mischievous single. -- T.H.

7. “Butterflies” (RBB, 2018)

The colorful tones of butterflies are evoked in this hidden gem from 2018’s RBB EP, with their vocals soaring on the layered, retro synth-pop melodies. Addicting with its refrain of “butterflies, butterflies” melded with crooning “oohs,” the track’s calmer verses offset its high-powered chorus, sweetly showcasing the members’ tones. Throughout it all, the quintet uses the metaphor of the rainbow-hued insects to describe the feelings of a beautiful romance that makes the world a bit brighter and fills the heart with fluttering feelings of love. -- T.H.

6. “Look” (Perfect Velvet, 2017)

Who needs ‘90s edits when you can have a retro concept with a Red Velvet twist? This throwback is structured around the group’s R&B sensibilities, complete with bouncy synths straight out of a VHS tape. The SUMIN-produced track is a scintillating display of ad-libs and vocal blips, as the girls get the rare opportunity to reach down into their lower registers. Then there’s the dance break, making “Look” a deep cut destined for the music show circuit. As it turns out, the members know exactly how to mine nostalgia, no filter needed. -- C.K.

5. "Body Talk" (Rookie, 2017)

When their Rookie EP dropped in 2017, Red Velvet was less than three years into their careers. But this stunning B-side first hinted at the mature and sophisticated side of these multifaceted musicians. Seulgi called it her favorite track from the EP, noting that it was the first time the group showed a more sensual side over the soaring, '80s-inspired synth work. With a single as wild as "Rookie" was, having a song like "Body Talk" on the same record further showcased the wide range of styles and moods the group was on their way to conquering. -- J.B.

4. “Dumb Dumb” (The Red, 2015)

K-pop’s answer to “Bang Bang” by Ariana Grande, Nicki Minaj, and Jesse J, this high-powered electro-pop track starts strong and never stops to take a moment of breath, serving up a true earworm of a hit that makes the most of Red Velvet’s dynamic vocals. The horn-infused song moves along with a frenzied pace and revolves around the titular chant. Powerfully delivered verses and sassy Michael Jackson-referencing raps break through the intense, repeated assertation about how feelings of love make one feel like a "Dumb Dumb." -- T.H.

3. “Kingdom Come” (Perfect Velvet, 2017)

With a title like “Kingdom Come,” you can’t expect anything short of a religious experience, and Red Velvet take us straight to Sunday mass on this R&B stunner. Backed by off-kilter percussion, their vocals take center stage through sublime, intricate harmonies and stand-out ad-libs from the gifted Wendy and Seulgi. On what is arguably the group’s greatest LP, “Kingdom Come” still manages to stand out with its nostalgic ‘90s R&B sound and complex vocal layers, and it showcases Red Velvet at their most sophisticated. -- M.M.

2. “Bad Boy” (The Perfect Red Velvet, 2018)

Leave it to R&B architects The Stereotypes and SM Entertainment legend Yoo Young-jin to arm Red Velvet with the sleekest, sultriest track in their discography. “Bad Boy” leads the charge on the loftily titled The Perfect Red Velvet and delivers in spades, epitomizing the R&B sound they’ve cultivated since 2014’s “Be Natural.” Layers of sounds -- sleek synths, a smooth bassline, chopped snares, heel clacks, and finger snaps -- all meld together masterfully, while the members go full-on coy with their vocal performance. Red Velvet had proven in years past that they could take on R&B singles with ease, but this track is “velvet” par excellence. “Bad” never sounded so good. -- M.M.

1. “Red Flavor” (The Red Summer, 2017)

“Red Flavor” is practically Red Velvet’s signature song at this point. After its 2017 release, it’s become one of their best-selling tracks, and it notched their first No. 1 on Korea’s Gaon chart. They even performed it in North Korea. It’s the perfect brew of showmanship with the infectious hook, memorable choreography, and fruity music video creating a sensory explosion. The chorus keeps it simple with their harmonies buoyed atop snappy percussion. “Red Flavor” exudes the kind of fun-loving energy that made it a shoe-in for Korea’s song of the summer. In fact, the songwriters Caesar & Loui revealed this bright bop was inspired by Little Mix and Beyoncé.

But it wouldn’t be a Red Velvet track without a few quirks. The pitched-down vocal loop has been memed by fellow idols, and the visual is jam-packed with absurd imagery. (Not many artists can pull off interviewing a fruit version of themselves.) This archetypal entry on their “red” side captures what the group does best: eccentricity and catchiness in equal measure. It’s no wonder “summer” has become synonymous with Red Velvet. -- C.K.