Great Mass in C minor, K. 427/417a, is the common name of the musical setting of the mass by Wolfgang Amadeus Mozart and considered one of his greatest works. He composed it in Vienna in 1782 and 1783 after his marriage when he moved to Vienna from Salzburg. This large-scale work, a missa solemnis, is scored for two soprano soloists, a tenor and a bass, double chorus and large orchestra. It remained unfinished, missing large portions of the Credo and the complete Agnus Dei.
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