Between 1772 and 1780 Mozart composed a dozen of short, one-movement pieces for Salzburg Cathedral, to be performed during mass. The “church sonatas”, as they are known today, involve strings without a viola and an organ, as well as the occasional woodwind instrument. The organ has a solo role, in particular in the last C-major sonata, the K 336. In the K 244 the keyboard instrument has a brief part, and in the K 274 it plays continuo. The orchestra in the C-major K 329 further includes two oboes, two horns, two trumpets and kettle drums.