Simplify the following text for a Grade 4 native English-speaking person.
Original: Berg attended the first production in Vienna of BÃ 1\/4 chner 's play on 5 May 1914 , and knew at once that he wanted to base an opera on it .
Simplified: Berg knew at once that he wanted to make the play into an opera . BÃ 1\/4 chner , who had died in 1837 at the age of 23 , had left the play unfinished .