Begun to celebrate his marriage to Constanze, but left unfinished at the composer’s death, Mozart’s ‘Great’ Mass in C minor can clearly be traced back to the choral writing of J.S. Bach and his son, Carl Phillip Emmanuel. In this televised appearance at the BBC Proms, we unpack the Mass’s musical genealogy, tracing its roots back over a century in a lavish double-chorus, double-orchestra feast.