AlHaj studied under the renowned Munir Bashir, considered by many to be the greatest oud player ever, and Salim Abdul Kareem, at the Institute of Music in Baghdad, Iraq.

In 1991, after the first Gulf War, AlHaj was forced to leave Iraq due to his political activism against the Saddam Hussein regime and began his life in Jordan and Syria.

His East meets West CD entitled Friendship (Rahim AlHaj, Oud & Sadaqa Quartet) was released in December 2005 by Fast Horse Recordings.

His When the Soul is Settled: Music of Iraq, produced by Smithsonian Folkways, was released in June 2006, and nominated for a 2008 Grammy Award.

AlHaj wrote and performed the music for the award-winning short documentary, The Rest of My Life: Stories of Trauma Survivors.