Birthday had the biggest pop in Red Velvet’s concert

Birthday isn't their weakest red song. In fact, it's a better song than old title tracks like Russian Roulette. It means some people has a habit of liking the good charting song. Zimzalabim also to a more fun song live. Personally, I prefer Zimzalabim and Umpah Umpah to live performances rather than Russian Roulette or Ice Cream Cake.

interesting

Same with Zimzalabim and with Really Bad Boy, I guess: there are simply songs that shine better when they performed live, and that can get an audience going wild, and then there are songs that do better with their MV or streaming. Both groups don't have to overlap 1 on 1.

Quote from ellenote

of course, people are going to go crazy it's a concert for reveluvs. doesn't mean the songs good. if I went to a stray kids concert and they performed case 143 id scream even though that's the worst stray kids song.

I think the OP merely meant that the song seemed to work better when performed live, with a crowd, maybe even better and getting the crowd more energetic than other songs that charted better.

Which wouldn't be a rare situation at all, songs that do better when performed on stage in front of an audience vs songs that do better when just listening to it on your own.

I love Birthday 🎁 🎉 🎈