August has been a busy month for Primary. In that short time, the producer has put out one eight-track solo EP called shininryu, as well as a special collaboration EP titled POP. Why POP? Maybe because each of the six tracks features a well-known K-Pop idol, bringing together the genius of Primary’s composing and the skilled vocals of big names within the Korean music scene.

The release of POP on August 30 was definitely a surprise. Who expects an artist to put out a second release merely weeks after a long-awaited comeback? I was still only getting used to the songs on shininryu when I heard news about POP. And though the featured names on shininryu did catch my attention (and probably held it for longer than the ones on POP did), the prospect of hearing Primary’s characteristic R&B, urban sound paired with pop vocals sure was intriguing. So I decided to wait for this release, hoping to see just what it was about.

The first track—and one of the best—features INFINITE’s leader and vocalist Kim Sungkyu, which already had me excited for the track itself. Sungkyu’s voice is pretty much my favorite in INFINITE, and though the group’s sound is widely varied and versatile, it doesn’t really compare to what “Drama” has to offer. It has that rhythm guitar-driven contemporary soul sound typical of Primary’s work, letting Sungkyu’s vocals shine through in a way they rarely do. His lower register is clean and powerful, and his higher notes aren’t jarring. It’s both beautiful and very catchy, and it gets your foot tapping along before you even realize you’re doing it (which, mind you, is something that occurs a lot when I personally listen to Primary).

I have to say, though, that the best of POP is delivered by the ladies (yay!). “Right?” is the third song on the tracklist, and Soyou’s voice in this song absolutely stuns—which isn’t to say it doesn’t usually, but it’s the brass-driven R&B and soul melody that really does a great job at highlighting her vocals. Her breathy voice is enchanting, and the soft tone she uses when singing will warm you up as you listen to the (very much catchy) track. The lyrics talk about the confusing push-and-pull of a relationship, but you wouldn’t even guess it with just how smooth the song sounds. Overall, it remains a highlight on POP.

Another lady who steals the spotlight on the EP is EXID’s Solji on the toned-down “Diet.” We hadn’t heard of the bright vocalist for a long time, now—due to sickness, she was unable to participate in EXID’s promotions for their (very good) mini-album Eclipse, released in April of this year. “Diet” is a great redemption track, if you want to call it that. Again, the sound just screams Primary’s work: simple beat, prominent guitars, and a funky bass giving way to Solji’s melancholic voice. The lyrics are simple—repetitive, almost—but their imagery is interesting to say the least, as in the comparison between a broken relationship and a diet. Rather than telling a story, it really focuses on the feeling, with contradictory lines such as “I’m not hungry, I’m hungry.” It’s not hard to relate to, and with the simple background music and beat, “Diet” makes for a great song and is certainly the best on POP.

The last track was chosen well—it’s unique, standing out from the rest of the tracklist with a different structure to it than the rest of the songs. Featuring GOT7’s JB for vocals, “Hush” is the perfect R&B ballad, with a slightly more complex beat than the other songs and a more prominent bass line. All of it—the percussion, the subtle synths, the bass—serves to truly let JB’s voice shine through. Sometimes it feels as though it’s the only thing you hear, despite the heavy presence of the music surrounding it. It shows Primary’s perfect production work, as well as the immense skill JB possesses in truly bringing out the best of a song. You don’t have to like the man to admit he’s an amazingly flawless singer.

I left two songs out, not because they were bad, but because they simply didn’t stand out as much as the other four did. Nevertheless, POP remains a great release. It’s an interesting look at (K-)pop music, with a very distinct Primary twist to it. If you’re a fan of either, this will surely please you—it pleased me, anyway.