Star Wars V: The Empire Strikes Back – “For my ally is the Force ” (Force Theme, Yoda’s Theme). Internet resource at http://bit.ly/1hpjB2F.
“YODA: Now…the stone. Feel it.
Luke concentrates on trying to lift the top rock. It rises
a few feet, shaking under the strain. But, distracted by
Artoo’s frantic beeping, Luke loses his balance and finally
collapses. Yoda jumps clear.
YODA: Concentrate!