Simplify the following text for a Grade 9 native English-speaking person.
Original: In late 1970 , the London Symphony Orchestra invited Shankar to compose a concerto with sitar ; Concerto for Sitar and Orchestra was performed with AndrÃ Previn as conductor and Shankar playing the sitar .
Simplified: Ravi Shankar is famous for playing the sitar , an Indian stringed instrument .