Complex sentence: In 1975 he was commissioned to write the choral work "Son of Man" to mark Britain's entry into Europe, and later by Queen Elizabeth II to compose a "Te Deum" for the Royal Chapel of All Saints at Windsor.
Split into simpler sentences: In 1975 he was commissioned to write "Son of Man" to mark Britain's entry into Europe. Shortly after Cannon was commissioned by Queen Elizabeth II to compose a "Te Deum" for the Royal Chapel at Windsor.