Simplify the following text for a Grade 9 native English-speaking person.
Original: Between 1905 and 1908 he composed his final masterpiece , Iberia ( 1908 ) , a suite of twelve piano `` impressions '' .
Simplified: Between 1905 and 1909 he composed his most famous work , Iberia ( 1908 ) , a suite of twelve piano `` impressions '' .