On today's date in 1784, in the city of Vienna, Wolfgang Mozart finished one bit of work and started another—which he would continue until the end of his life.

After Mozart put the finishing touches to his Piano Concerto No. 14 in E flat, he entered this work as the first item in a ledger, which he titled, "A List of all my works from the month of February, 1784 to the month of..." Mozart then left a blank space on his title page for the concluding month and wrote just the number "1" in the space left for the concluding year of his catalog—with the reasonable expectation that he would live long enough to see the turn of the new century. He then signed his title page: "Wolfgang Amadé Mozart by my own hand."

On the catalog's unruled left-hand pages Mozart wrote the date and description of his subsequent works, and occasionally, in the case of his operas and vocal pieces, the names of the singers who premiered them. The right-hand side of the page was lined with music staves, and here Mozart would write the opening measure of each piece.

The very last entry in Mozart's ledger book is dated November 15, 1791, just one month before his death. This final entry notes the completion of a cantata written for Vienna's "New-Crowned Hope" Masonic Lodge.