Octahedron is the fifth full-length studio album by American progressive rock band the Mars Volta, released on June 23, 2009. The album was released by Warner Bros. Records in North America and Mercury Records worldwide. It is the last studio album to feature drummer Thomas Pridgen and guitarist John Frusciante, and the first not to feature contributions from keyboardist Isaiah "Ikey" Owens. Previous members multi-instrumentalist Adrián Terrazas-González and guitarist and sound manipulator Paul Hinojos are also absent from the album.