I first heard this in the 80s with a Norwegian Tensing Choir. "Johnny's" got a head like a ping pong ball was used for choir warm up, singing very fast to practise diction and adding a slide line to the verse" ping png ping pong ping pong ping pong ball" to take it down a note or two then sung again and again at a lower and lower pitch to expand the chior's voice range. Supercalifragilisticexpialidocious was used in the same way with the umdiddle idlle idlle umdiddle aye , umdiddle idlle idlle umdiddle aye used to take it up a pitch. Some universities Revelation Rock Gospel choirs still use them now. I thought of suggesting it for Shellback Chorus but I am sure they would all laugh at me!