Simplify the following text for a Grade 9 native English-speaking person.
Original: In 1876 , Ibsen asked Grieg to write some incidental music for the first performance of the play he had written about the Norwegian hero Peer Gynt , .
Simplified: In 1874 â `` 76 , Grieg composed incidental music for the premiere of Henrik Ibsen 's play Peer Gynt , at the request of the author .