The trouble is they don't actually sing rock tunes either, instead they sing pop tunes in the gayest high pitched voice they can muster.
Tunes of the moment are
"I see you driving round town with the girl I love, and I'm like"Then the whole team will join in with the words
"FUCK YOU!!!!!"Then you see the restaurant manager coming flying in through the restaurant door, shouting
"The guests!, The guests!"