A composer, singer and flute player, Khalifa is considered a Palestinian among the Palestinians, a Southerner among the South Lebanese and most commonly an Arab musician. From 1970 to 1975 he taught at the conservatory in Beirut. In 1976, he created Al Mayadeen Ensemble and became famous all over the world for songs like Ummi (My Mother), Rita w’al-Bundaqiya (Rita and the Rifle) and Jawaz al-Safr (Passport), based on Mahmoud Darwish’s poetry.