Magma is one of those bands that creates its own category, a French group around since the 1970's that does a supercharged proggy jazz-rock revolving around a science fiction mythology created by the band's founder, drummer Christian Vander, that even involves the group's vocalists singing in a made-up language, Kobaian. The closest comparison I know would be Sun Ra and his Arkestra. I don't know if the two bands ever played on the same bill but if they had, a large chunk of the planet might have flown off into space.
There are a surprising number of clips of the group on You Tube. This one is the climax to a 2006 concert with old hands like Vander, bassist Jannick Top and vocalist Stella Vander (Christian's wife) still going strong alongside younger musicians.