I have the Ipod Classic Video thing and i dont know why its doing this?

I have the iPod Classic video thing, not really sure what its called, and i tried to plug it into the computer so i could add a song, but it froze. the only thing that will show up is the red circle with the line saying "Do not disconnect." Its being such a spazz! i tried holding down buttons, but it still wont work!! it wont even turn off! HELP MEE PLEASE I WANNA LISTEN TO MUSIC AND GO TO SLEEP!! thanks