There are multiple artists with this name; 1) Om (sometimes stylized as OM) is an American doom metal band from San Francisco, California. Formed as a duo in 2003 by the rhythm section of the band Sleep, OM is currently a trio. Om's earliest works incorporate musical structures similar to Tibetan and Byzantine chant, as heard on the debut album Variations on a Theme. The band's name itself derives from the Hindu concept of Om, which refers to the natural vibration of the universe.