How old was mozart when he first composed a musical piece?

Wolfgang Amadeus Mozart composed his first musical piece when he was five years old

Mozart's first known musical composition dates from 1761. Mozart was five years old when he first began composing little pieces. He played them to his father, who then wrote them down.

The term collage was coined by both  georges braque  and  pablo picasso  in the beginning of the 20th century when collage became a distinctive part of modern art.hope this sorry if there wasn't more of an explanation!