There are multiple artists with this name: 1) Omission is a thrash metal band from Spain. Official Myspace 2) Omission is a rock / hardcore band from The Netherlands. Official Myspace 3) Omission was a thrash metal band from the United Kingdom. They released one EP entitled "Black Box Recordings" in 2005. Band Info 4) omission is a slowcore /alternative rock artist from the United States.