At least some of the aliens' sung and spoken lines are recordings played in reverse. Starting about 1:34 When the tall Frankenstein monster-like robot speaks after "processing" the cow and pig, he sings the first seven notes of "Yankee Doodle".forward in "ha ha" syllables, but immediately following he is heard singing "Yankee Doodle Went to Town" played back in reverse. The retrograde seven notes of the melody are repeated on the keyboard by his assistant probably using a xylophone reproduced normally to provide the sound. . Later at about 2:55 when he is interrogating Willie the monster says "1,2,3,4,5,6,7" backwards three times.