He is acknowledged as creating a Spanish popular musical genre known as "La cancion del verano". In these letters, written after Mozart had spent a pleasant two weeks with his cousin in her native Augsburg. Advertisements invited people put the talents of the quot;wonderful boyquot; to the proof by giving him anything to play at sight, or any theme upon which to extemporise. Wolfgang Amadeus Mozart Wolfgang Amadeus Mozart ( German ЛvЙlfЙaЕ amaЛdeЛКs ЛmoЛtsaКt.