Simplify the following text for a Grade 7 native English-speaking person.
Original: Keith John Moon ( August 23 , 1946 â `` 7 September 1978 ) was an English musician , best known for being the drummer of English rock group The Who .
Simplified: Keith John Moon ( 23 August 1946 â `` 7 September 1978 ) was an English drummer best known as being a member of the rock band The Who .