Complex sentence: The choir's next major concert is on 12 March 2011 in Winchester Cathedral, with Mozart's Symphony No 29, Solemn Vespers and Mass in C Minor.
Split into simpler sentences: The choir's next major concert is on 12 March 2011 in Winchester Cathedral. This will be a concert of music by Mozart-Symphony No 29, Solemn Vespers and Mass in C Minor.