Do you know what the "round" singing is?
I am sure you knew if you listen to these movies, let's take a look at them first.
I think you have gotten the idea of what the round singing is now.
There is a "round" singing section in one of the songs you are learning in TICC rehearsals.
So, let's try some for your preparation. Don't worry if it will be your first time to try, it must be fun!
Hotaru Koi ほたるこい (Fireflies come)
Hotaru Koi (ほたるこい）is a Japanese traditional song.
You can try in 3 parts round singing with the following movie. For you solfege training, you will sing in Do-Re-Mi.
However, you could refer all of the Japanese and English lyrics at here www.mamalisa.com/?t=es&p=4153 if you would like to know.