Complex sentence: At the age of four Chloë performed solo at the Purcell Room and by ten had played in major concert halls throughout Europe and North America including Carnegie Hall in New York and the Royal Albert Hall in London.
Split into simpler sentences: At the age of four Chloë performed solo at the Purcell Room. By ten she had played in major concert halls throughout Europe and North America, including Carnegie Hall in New York and the Royal Albert Hall in London.