Om refers to the sacred syllable in Hinduism, which symbolizes the infinite or the entire Universe. Coltrane described Om as the "first syllable, the primal word, the word of power". Issued posthumously, the 29-minute recording contains chants from the Bhagavad Gita "Coltrane and one or two other musicians begin and end the piece by chanting in unison a verse from chapter nine ("The Yoga of Mysticism") of the Bhagavad Gita: Rites that the Vedas ordain, and the rituals taught by the scriptures: all these I am, and the offering made to the ghosts of the fathers, herbs of healing and food, the mantram, the clarified butter. I the oblation, and I the flame into which it is offered. I am the sire of the world, and this world's mother and grandsire. I am he who awards to each the fruit of his action. I make all things clean. I am Om!" a Hindu holy book, as well as Coltrane and Pharoah Sanders chanting from a Buddhist text, The Tibetan Book of the Dead, and reciting a passage describing the primal verbalization "om" as a cosmic/spiritual common denominator in all things.

It was included on The Major Works of John Coltrane CD released in 1992.

Om was recorded just a day after Coltrane and his band played live in Seattle. The next day, they went over to a nearby recording studio to record Om. It is believed that Coltrane was using LSD during the recording, though some people have said this is only a myth. It has also been rumored that Coltrane didn't want this recording released. However, Bob Thiele, the director and producer of Impulse! released in 1968 to capitalize on his death and to capitalize on the growing psychedelic rock scene at the time. When it was released, many people considered it to be the worst album Coltrane had ever produced. However, critics have been much more accepting of this album over the years.

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