Sounds like the judges buzzed David because he didn't give a list, and instead sang the lyrics to the song. I'm guessing it would've been legit in the main game if "Favorite Things" was displayed. It's also a little misleading, considering he's describing a song by that name, not favorites like "a TV show".
Since "O Sole Mio" falls into the category of an Italian song, I could see that passing.
Adrienne sang "O Solo Mio" for the category "Italian Songs," and the judge didn't buzz her.
I would think naming the items in the song while bobbing your head to & fro (ala Eddie Murphy's impression of Stevie Wonder) would be considered legal -- your not singing, but your moving your head to an unheard beat.
If Adrienne Barbeau was told she would have been popped for fluttering her eyelashes for THINGS THAT FLICKER, then it's reasonable to assume that this is WAY more illegal than that.
I know there was an episode on Youtube where I think Henry Polic was trying to describe "Where You Find an Audience" and, in desperation, jerked his head back while saying "in this studio," and the judge didn't say anything.
EDIT: Adrienne's clip:
http://www.youtube.c...uJXX4FU&t=1m40sHenry's Clip:
http://www.youtube.c...RZXUQMA&t=16m0s
