During the first cinematic where it gives you the options to toggle the blood gore and swearing, wait until right before Eddie says the line that would lead to the option of turning on or off swearing. He sees one of the band members dancing on a very shaky ledge. While that band member is dancing on that ledge, he will be chanting a song that was done in Psychonauts by a couple kids in a few parts, but more notably by Raz himself in the level where you have to face four wrestlers to get a card. At the end of each match after you defeat them, Raz did the same dance and chant the song.
The headbanger that wears the goggles on all the Death Rack missions sounds identical to Raz, but slightly deeper.