When and Chris Hakius emerged from the legendary collapse of Sleep to form Om in 2003, they didn't just return to heavy music; they reinvented its spiritual core. Their debut album, Variations on a Theme , released in February 2005 via Holy Mountain , served as a bridge between the monolithic sludge of their past and a new, meditative era of stoner metal.

By stripping metal down to its barest components—bass, drums, and voice—Om proved that "heavy" is a state of mind as much as a volume setting. Variations on a Theme remains a essential pillar of the genre, an "ingestible sacrament" for those who prefer their music to be a journey rather than just a song.

The album functions as a single, evolving suite—a series of "vibrations and flow".