Simplify the following text for a Grade 11 native English-speaking person.
Original: David Scott `` Dave '' Mustaine ( born September 13 , 1961 , La Mesa , California ) is the founder , main songwriter , guitarist , and lead vocalist for the American thrash metal band Megadeth .
Simplified: David Mustaine ( born September 13 , 1961 in La Mesa , California USA ) is the lead guitarist , songwriter and vocalist for the heavy metal band Megadeth .