Historical discussion focuses on the lineage of the Bach family, compositions determined by circumstances of employment, the composition of Lutheran Masses, the possible rationale for composing a Catholic Mass, and the history of the B Minor Mass in terms of manuscripts, performances, and editions. Musical discussion focuses on parody technique, the assemblage of four disparate units of composition into the B Minor Mass, comparisons of stile antico and stile moderno characteristics of the Mass, and formal and musical structures of the Mass, with special attention to structural balance and mirror dispositions. Performance practices include singers and instrumentalists and their arrangements in performance, meter as it affects tempo, rhythmic alteration, and ornamentation.