Simplify the following text for a Grade 8 native English-speaking person.
Original: Tim Burton first saw Stephen Sondheim 's 1979 stage musical , Sweeney Todd : The Demon Barber of Fleet Street , as a CalArts student in London in 1980 .
Simplified: Sweeney Todd : The Demon Barber of Fleet Street is a 2007 film directed by Tim Burton . It is an adaptation of Stephen Sondheim and Hugh Wheeler 's Tony Awardâ `` winning 1979 musical thriller .