Completion of Symphony No. 40 in G minor

Mozart composed Symphony No. 40 in G minor, K. 550, in 1788. The date of completion is known exactly because Mozart kept a full catalog of his completed works in his mature years, entering the symphony on 25 July 1788. Work on it occupied an exceptionally productive period of just a few weeks during which he also completed the 39th and 41st symphonies. The 25 July date is retained from the sourced passages, but the legacy record and event scope give 28 July 1788; this discrepancy remains unresolved and the completion date should be treated as debated. It is one of his most celebrated and widely performed works, and one of only two extant minor-key symphonies among his symphonies.