Simplify the following text for a Grade 11 native English-speaking person.
Original: Marinetti was soon joined by the painters Umberto Boccioni , Carlo CarrÃ , Giacomo Balla , Gino Severini and the composer Luigi Russolo .
Simplified: He was soon joined by the painters Umberto Boccioni , Carlo CarrÃ , Giacomo Balla , Gino Severini and the composer Luigi Russolo .