The episode: “Werewolf,” ep. 904
The riff: Alright, so this isn’t a standard riff here. The character (in this case Tom) doesn’t say “wordless yodeling,” it’s the sound he makes. As a truck driven by Native Americans pulls up and a drum beat plays, Tom starts to yodel a very oddly recognizable tune.
The explanation: The tune in question is actually from the song “Return to Innocence” by German electronic music project Enigma. It was an unexpected crossover hit in many countries when it was released in 1994. The ululating vocals were actually taken from a song by a native Ami, which is the indigenous natives of Thailand. It is often mistakenly attributed to Native Americans, which is probably why Tom sings it here.
Novelty factor: I really find this riff interesting. I didn’t know the name of the song or the group Enigma, but I absolutely remember this tune. In fact, I’d been trying to identify it for a long time. I also thought it was Native American in origin, because I could swear I remember TV commercials in the 90’s for “Top Native American Hits” soundtracks that featured it. NOTE: The yodel-part of this song doesn’t start until 1:30 or so.