Something which I only made the connection with not long ago. I was scared of church organ music - in fact every time I went to church I'd bawl my eyes out at almost every hymn!
Where I used to live when I was very little (under age 5), to get to the shops or the doctor's, we took a shortcut along a narrow footpath which cut straight through the middle of an electricity substation (yup you read that right!). My mum would say 'don't put your hand through the fence or you'll get electrocuted' so I used to walk dead centre of this narrow path scared out of my wits.
All the electricity thingies - I don't know what they're called - well they looked like giant radiators to me (maybe capacitors?) - and they hummed constantly - in fact they sounded just like a church organ.