Like in any other year, K-pop in 2021 can’t be defined by a single sound or message. Soloists and groups continued pushing the bounds of genre within Korean pop music as they experimented with influences from rock to Latin, R&B to electropop. But if there was one theme that emerged more than others in the lyrics of this year’s top releases, it was a shared reflection on the passage of time, the formation of memories and holding onto hope through it all.