Aviv Geffen (Hebrew: אביב גפן‎, born May 10, 1973) is an Israeli rock musician, singer, songwriter, producer, keyboardist, and guitarist and the son of writer and poet Yehonatan Geffen and Nurit Makover, brother of actress Shira Geffen, and an alumnus of Rimon School of Jazz and Contemporary Music.Geffen was and is extremely popular among Israeli youth who were known during the 1990s as the "Moon Children" ילדי הירח, i.e., hippies. Politically, he associates with the Israeli left.