Mozart did not complete the Great Mass in C KV427, so modern editions are completed by editors and therefore significant differences exist between them. The Edition 1 is based on the CPDL edition completed by Philip Legge; Edition 2 is based on the B�renreiter edition BA 4846-90 completed by Helmut Eder; Edition 3 is based on the Peters edition 4856 (also known as Kunzelmann GM-1900 or Eulenburg 6057a) completed by Howard Chandler Robbins Landon.