Nocturnus

Nocturnus, currently Nocturnus AD, is an American death metal band formed in Tampa, Florida in 1987 by drummer/vocalist Mike Browning (formerly of Morbid Angel). They were known for their science-fiction themed lyrics and use of keyboards, both of which were virtually unknown in extreme metal at the time. The 1990 debut from the band is considered by some to be the first progressive death metal album.