Hillel Slovak ( April 13 , 1962 â `` June 25 , 1988 ) was an Israeli musician . Slovak was the guitarist for the rock band Red Hot Chili Peppers . Hillel Slovak â ( April 13 , 1962 â `` June 25 , 1988 ) was an Israeli-American musician best known as the original guitarist and founding member of the Los Angeles rock band Red Hot Chili Peppers .