Complex sentence: He first appeared on television at the age of 6; he was invited to play in the Lebanese presidential palace at the age of 7 and composed music at the age of 8, winning his first competition.
Split into simpler sentences: He first appeared on television at the age of 6 and was invited to play at the Lebanese presidential palace by the age of 7. Manoukian composed music at the age of 8 and won his first competition.