Isis was an American post-metal band formed in Boston, Massachusetts in 1997 by guitarist and vocalist Aaron Turner, bassist Jeff Caxide, vocalist and electronic instrumentalist Chris Mereschuk and drummer Aaron Harris. After a demo and the EP Mosquito Control were recorded by the original lineup, Mereschuk was replaced by Jay Randall in 1999, who joined the group alongside guitarist Michael Gallagher. Jay Randall would later be replaced by guitarist and keyboardist Bryant Clifford Meyer after the recording of Red Sea. With roots in hardcore punk and doom metal, the band borrowed from and helped to evolve the post-metal sound pioneered by bands such as Neurosis and Godflesh, characterized by lengthy songs focusing on repetition and evolution of structure. Isis disbanded in June 2010, just before the release of a split EP with the Melvins, reforming only once in 2018 as Celestial for a one-off show to pay tribute to Caleb Scofield.