Wolfgang Amadeus Mozart (1756-1791) composed Missa Brevis in G, K. 49/47d in Vienna in October-November 1768, when he was only twelve years old, making it his first complete setting of the Ordinary of the Mass. Scored for SATB soloists and chorus with strings and continuo, the work reflects the concise liturgical style implied by "missa brevis," while already revealing Mozart's distinct voice. The immediate occasion and first performance are not securely documented, though the Mass belongs to the same early Viennese period as the larger Waisenhausmesse, K. 139/47a, and its first edition did not appear until Breitkopf & Härtel's Mozart Complete Edition in 1877. Today, Missa Brevis in G, K. 49/47d is less frequently performed than Mozart's later Salzburg masses, but it remains an important work for choirs and scholars as a glimpse of the young composer's developing command of church music. Reprint edition.