NCT U is the first sub unit of SM entertainments first ever rotational group. Of over 40 trainees, these 5 were chosen as the first representatives of NCT. This means that they have officially debuted but will not necessarily be in every song or music video. What's more, SM wants to aim the various sub units at different countries, potentially even aiming for a US debut. So far NCT U and NCT 127 have debuted (members Taeyong and Mark appeared in both comebacks, whereas the other members were rotated out for new ones).
Why I chose this song: I first listened to a day or so after it came out because I was interested in the rotational group concept, and no lies, I haven't stopped playing it since. It may not be musically very unique, but there is something addictive in that opening beat that makes me want to keep playing it!
I recommend "Drip Drop" by Taemin and "Monster" Bby Exo if you like this