Simplify the following text for a Grade 7 native English-speaking person.
Original: Her first book , Clarinet Virtuosi of the Past , published in 1971 , was followed by The Clarinet Teacher 's Companion ( 1976 ) , More Clarinet Virtuosi of the Past ( 1977 ) , Clarinet Virtuosi of Today ( 1989 ) and Yesterday 's Clarinettists : A Sequel ( 2002 ) .
Simplified: She wrote several books about famous clarinet players of the past . She also wrote `` The Clarinet Teacher 's Companion '' , a book which was used by many clarinet teachers .