Simplify the following text for a Grade 9 native English-speaking person.
Original: Johann Georg Leopold Mozart ( November 14 , 1719 -- May 28 , 1787 ) was a German composer , conductor , teacher , and violinist .
Simplified: Johann Georg Leopold Mozart ( November 14 , 1719 â `` May 28 , 1787 ) was a composer , music teacher and violinist .