Simplify the following text for a Grade 8 native English-speaking person.
Original: LÃ on Theremin ( born Lev Sergeyevich Termen ; ) ( , Saint Petersburg , Russian Empire â `` 3 November 1993 , Moscow , Russia ) was a Russian and Soviet inventor .
Simplified: LÃ on Theremin ( born Lev Sergeyevich Termen , ) ( August 15 1896 -- November 3 1993 ) was a Russian inventor .