well i saw the Pointer Sisters on teh Space Stage in either the very late 70s or very early 80s..i think Captain Eo came out in what....84?
I saw Tommy Tutone in the early '80s. Shortly after that they started showing Magic Journeys (or some title similar to that). This was a really awesome 3d movie. They simply threw up some temporary paneling around the theatre.
When Captain Eo came out, they finally redid the theatre to its current, permanent condition.
In 1984 they still had the live show "Show Biz Is" on the Space Stage, the open theatre which used to be in that location. In 1985 the live show was "Disneyland Is Your Land" for Disneyland's 30th, and at night they showed Magic Journeys. This was kind of neat because you were seeing a 3-D movie "outdoors" and there were some nature shots in the film. Also Magic Journeys made some rather odd noises, which got attention from passersby in the area.