Rum Pum Pum Pum (첫 사랑니)

The production on this track operates in a register that few K-pop songs of its era attempted — genuinely eccentric, built on a bed of plinking, toy-box electronic tones and a rhythm that skips and stutters in ways that feel deliberate and slightly odd, like a music box that runs slightly fast. There are layers here that reveal themselves across repeated listens: countermelodies hiding in the high register, percussion elements that seem to enter and exit on unusual beats, a bass presence that occasionally drops in just to remind you it exists. The vocal approach is playful and slightly affected, the members inhabiting a zone between cuteness and cool that requires considerable skill to maintain without tipping into either extreme. The central metaphor — a wisdom tooth as the symbol of first love, something that pushes through painfully and changes the shape of everything — is clever in a way that suits the group's reputation for embracing intellectual eccentricity within the idol format. This was part of SM Entertainment's most adventurous production period, and the song captures that willingness to let strangeness coexist with accessibility. It's the kind of music you revisit not because it's comforting but because it rewards attention, best heard with headphones on a commute or late at night when your brain is alert enough to catch what it's doing.