Simplify the following text for a Grade 10 native English-speaking person.
Original: Webern used his transcription for orchestra of the six-part ricercar from Bach 's Musical Offering to analyze the structure of the Bach piece , by using different instruments to play different subordinate motifs of Bach 's themes and melodies .
Simplified: Webern made a transcription for orchestra of a ricercar from Bach 's Musical Offering .