Simplify the following text for a Grade 10 native English-speaking person.
Original: Piret JÃ rvis ( born 6 February 1984 in Tallinn ) is an Estonian singer , guitarist and songwriter of the popular girl group Vanilla Ninja and an indiegroup Disko4000 .
Simplified: Piret JÃ rvis ( born February 6 , 1984 in Tallinn , Estonia ) is an Estonian musician , and member of the popular girl group Vanilla Ninja .