Short answers, pulled from the story.
Wolfgang Amadeus Mozart entered an expense book on the 27th of May 1784 to purchase a starling bird for 34 Kr. This transaction marked the beginning of a three-year companionship with the common starling.
The starling sang the opening bars of Piano Concerto No. 17 in G, K. 453 which Wolfgang Amadeus Mozart had finished on the 12th of April 1784. The bird inserted specific errors like a fermata and incorrect notes that appeared in later compositions by the composer.
The starling died on the 4th of June 1787 and Wolfgang Amadeus Mozart buried the creature in his garden with considerable ceremony. Georg Nikolaus von Nissen documented the funeral procession where everyone who could sing joined the heavily veiled group to make a requiem epitaph in verse.
Wolfgang Amadeus Mozart maintained multiple pet birds throughout his life according to historical letters from 1770 and 1775. He corresponded about canaries, tomtits, and robin redbreasts kept at his family home during his childhood and early adulthood.
A sad tale from 1791 involves another canary that served as a successor to the earlier starling in the household. Biographer Hermann Abert described the bird being present during Wolfgang Amadeus Mozart's final period until he agreed to have it removed due to distress.