The Hermetic Organ is an album by John Zorn, consisting of a single live improvisation on the Aeolian-Skinner pipe organ of St. Paul's Chapel at Columbia University, which was released on Tzadik Records in June 2012. The performance was held at 11 PM on the evening of December 9, 2011, which Zorn has noted was a full moon, as an encore to a "Composer Portrait" ensemble performance of his works held earlier that night at the Miller Theatre. It is the first release by Zorn to exclusively document his solo improvisations on the organ, his first instrument. In 2014, Zorn released a second volume of improvisations, The Hermetic Organ Vol. 2.