There are at least five groups that go by the name Seventh Seal. One is a Christian metal band from Maryland. They have been on top of many online Christian rock charts. A second one is a Japanese psychedelic rock supergroup featuring Asahito Nanjo (Mainliner etc.) and Makoto Kawabata (Acid Mother's Temple etc.). Another is an unsigned death metal band from Arizona. Also, there is an Italian heavy power metal band with female vocals created in 1996 that also goes by the name Seventh Seal.
The fifth is a hip-hop trio who started out of Port Townsend, WA consisting of Flow Chi, Ruff Cutts, and Under Rated.