How do you determine an Artist's Peak?

The period in which they released their best music, obviously.

When they go downhill. But remember, there are always a second wave

I always thought kpop group peak is their best performing song in sk or the song that launched the group to stardom like cheer up for twice.. idk if another twice song got better ULs or lasted longer on the charts but you can def tell no other song got as much buzz as cheer up.

So I guess we could say we used to determine peak based on the period kpublic gave the most attention to the group..

Now that kpop is so global and some of the top players underperform in sk.. o think it’s harder to determine since group performance is based on fandoms and they are consistent in producing results...