How does the dancing mini-game work in Suikoden 2?

I wait until there's a clap, that's what I did to recruit her, It took many attempt to recruit over, not because I couldn't time it right but because I couldn't remember which button to press (was harder to remember cause on keyboard), but I got it right eventually. And when I tried it in the castle, this time using a controller, first level even though she told her to press 8 button, she only clapped 7 times. Why is that?

Then when I looked in this video for some guidance, I noticed the player was able to skip the first triangle? How is that possible? https://www.youtube.com/watch?v=R96oHpFBigU&ab_channel=AbidingGamer

Any help?