What does 'seino' mean in Japanese? I hear it a lot in music?

Question:

Like in this video: http://www.youtube.com/watch?v=Nh8WYEhdA…
Mano yells, 'seeei no!' or something similar.
I hear it a lot in concerts and immediately after, the audience will sing a line along with them. It is like, 'say it with me!' or something?

Answer:

"Seino" is basically just a count in or like saying 1-2-3. We used it a lot at my Elementary School in Japan to count in when we want the students to repeat after us. When we wanted the students to do something we would say "seino" and they would do it.