Everyone here probably knows of Giovanni Battista Pergolesi's masterful "Stabat Mater", easily one of the most beautiful and influential pieces of the 18th century. However, few are aware of his Mass in F major scored for two four part choirs, soloists, oboes, horns, strings, and basso continuo. At the time, this piece was hailed as a masterpiece and helped Pergolesi garner fame in Italy. It is an absolute shame that this piece is so rarely heard. The "Kyrie" and the "Qui tollis" in particular are extremely impressive.
Search it up on youtube. If you want to buy a CD of it, I recommend Concerto Italiano's rendition directed by Rinaldo Alessandrini. There is no better performance.