Complex sentence: His last piece, the operetta "White Acacia" (1955), was left unfinished at his death, and it was completed by Kirill Molchanov and staged on 15 November 1955, in Moscow.
Split into simpler sentences: His last piece, the operetta "White Acacia" (1955), was left unfinished at his death. It was completed by Kirill Molchanov and staged on 15 November 1955, in Moscow.