Hi Kindertrauma, 
I've been batting this particular admission around for a while now while trying in vain to find a full recording of the source, scary bits included. No luck. The closest I can find is the admittedly perfectly innocent song that followed the traumatizing two-second snippet. Oddly enough, or maybe not oddly at all, the fact that I can't now find the trauma fuel for a relisten has made the memory all the worse. Yes, this trauma has lingered for twenty-five years or more. Brrrrr!
The song in question is 'One Potato, Two Potato',' as recorded on one of many cassette tapes of nursery rhymes, songs and stories I used to listen to as a kid. The song itself wouldn't have scared me – fairly gentle tenor male voice, simple instrumentals, harmless lyrics about counting potatoes out of a basket – but it definitely took on a menacing quality due to it being right on the heels of something that did flat-out terrify me. In the immediate lead-up to the song itself, a man suddenly yelps "Ouch! That's a hot potato!"
… Good gosh.
I don't know if the sudden yell, the content (as a child, I was petrified of hot things and the possibility of being burned) or the intense tone of voice this particular gentleman used – it sure sounded intense to me! – or some combination of all three did it, but whatever it was, the end result was that I full-on dreaded that segment of the tape every time it came around. I remember burying my head in the couch cushions or plugging my ears more than once, then trying to time it so I didn't unmuffle them until the scary segment had come and gone… which often led to misjudged timing and yells of abject dismay. aaaah! I remember deliberately asking to listen to the full recording once in a brave attempt to get over my fear of it, subsequently scaring myself silly and making myself cry, much to the confusion of my parents; I had *wanted* to listen to the full tape, after all. I hadn't explained my plan of facing down terror to them before getting on with it, so I can understand why they were bewildered. It was pretty hard to explain after the fact, let me tell you.
I now have the shivers. If I ever do find a full recording of this one, I am *not* sharing it with my niece, who's now about the same age I was when first traumatized by the thing. Yeeeek!