Postmortem has 1 Onslaught concert.

Onslaught is a British thrash metal band from Bristol, England, active from 1982 to 1991 and again since 2005. The band initially drew influences from US and British hardcore punk bands such as Discharge and The Exploited, as well as the new wave of British heavy metal, and eventually adopted a straightforward thrash metal sound. They have been recognised as pioneers of the British thrash metal scene, and are often referred to as one of the country's so-called "big four", along with Sabbat, Xentrix and Acid Reign.