Conversation so far:
What is notable about Harpo Marx on stage?
In January 1910, Harpo joined two of his brothers, Julius (later Groucho) and Milton (later Gummo), to form The Three Nightingales, later changed to simply The Marx Brothers.
What is Harpo Marx' stage name?
Harpo
Did Harpo Marx perform any other acts on stage?
Harpo was particularly talented, learning to play an estimated six different instruments throughout his career.
Did Harpo Marx gain any recognition during the time on stage?
Are there any other interesting aspects about the Harpo Marx article?
Harpo had changed his name from Adolph to Arthur by 1911.
Why did Harpo Marx dislike the name Adolph?
This was due primarily to his dislike for the name Adolph (as a child, he was routinely called Ahdie instead).

Question: What is the other reason?
Self-contained rewrite: What is the other reason why Harpo Marx disliked the name Adolph?