Simplify the following text for a Grade 7 native English-speaking person.
Original: In 1936 , he added Lionel Hampton on vibes to form the Benny Goodman Quartet ; in 1939 he added pioneering jazz guitarist Charlie Christian to his band and small ensembles , who played with him until his death from tuberculosis less than three years later .
Simplified: In 1936 , he added Lionel Hampton on vibes to form the Benny Goodman Quartet .