Complex sentence: Jack Gibbons began performing in public at the age of 10 and at 20 won First Prize in the Newport International Pianoforte Competition, his performance of Beethoven's Fourth Piano Concerto being described by the jury as "masterly".
Split into simpler sentences: Jack Gibbons began performing in public at the age of 10. At 20 he won First Prize in the Newport International Pianoforte Competition, his performance of Beethoven's Fourth Piano Concerto being described by the jury as "masterly".