Simplify the following text for a Grade 7 native English-speaking person.
Original: Arthur Marx ( previously Adolph Marx ) , also called Harpo Marx ( November 23 , 1888 -- September 28 , 1964 ) , was one of the Marx Brothers .
Simplified: Arthur Adolph `` Harpo '' Marx ( November 23 , 1888 -- September 28 , 1964 ) was an American comedian and film star . He was the second oldest of the Marx Brothers .