I heard it when I went looking for him and found that he had dragged the step stool from the downstairs bathroom into Landon's room. His mission: to disassemble each of the *19* "extra-special" Lego creations Landon has displayed on top of his dresser.
I heard it again when I found him dumping the cereal boxes all over the pantry floor, one by one.
And again. He came into my bathroom with some Star Wars "guys" he had pilfered out of Landon's closet. He was humming the tune while he slowly took them apart, leaving a helmet here and a leg there.
In fact he's singing it now; he's supposed to be sleeping, but I can hear the song, and I can hear some toy he managed to sneak into his crib. Or did he somehow get it out of the basket of toys near his crib? Either way. It's almost 10:00pm, he's not sleeping, he's playing with a toy, and he's singing Darth Vader's anthem.
Here's a video of him singing his song. It doesn't quite do it justice because, well, he's performing. He's really much better at singing this song when he thinks no one's looking and he's doing something naughty, like squeezing the toothpaste all over the bathroom floor.