Traditional...

....knife grinder
Traditionally knife grinders announce their arrival in your neighbourhood, using a familiar tune on a whistle/ pipes

These itinerant craftsmen attract housewives /shopkeepers / restaurant owners....
knives, scissors...gardening shears can all be sharpened....quickly and efficiently

I asked permission, before taking this photo,.....no problem taking the machinery...but the “man” wished to be inconspicuous.......
aha! Spain’s black economy.....in action again!