Laser Show Technology -- An interesting site, concentrating on early graphics from General Scanning and Interscan's "Lovelight" laser musical (1977).
A Brief History of Laser Light Shows, from L. Michael Roberts at his very detailed Laser F/X website. Some of the specific information may be a bit off (dates, claims to be the first at doing XYZ) and should be double-checked. But overall, a great introduction to laser history.
List of Laserium (Laser Images Inc.) shows starting in 1973.
History of AVI (Audio Visual Imagineering Inc.). From the Innovations page at AVI's website: "AVI became the first laser company to use sequential animation in planetarium laser shows, premiering this innovation at the Hansen Planetarium in 1983."
Ron Pellegrino has a number of interesting pages at his website. He has always been interested in visual music. In the mid-1970's, he used lasers to visualize electronic music. In 1981 his book The Electronic Arts of Sound and Light included a chapter on "Laser Light Forms", plus photos of abstract laser images. The University of Wisconsin has posted some photos of Pellegrino's visual work, which includes laser forms.
Rockne Krebs is best known for large-scale beamworks spanning many city blocks. He also did some early work in graphics projection. In 1969 he patented the idea of three-dimensional beamworks (U.S. Patent 3,622,228): "Multiple reflections of a thin beam of light are used to establish imaginary boundaries within physically limited space for displays as well as for forming illusory architectural models having conveniently re-arrangeable boundaries."
There is a detailed chapter on laser history in the book Laser Art and Optical Transforms by Thomas Kallard (Optosonic Press, 1979). It is out of print but may be available from older laserists (I believe L. Michael Roberts has a copy) or used book sources.
If you have additional links or resources on lasershow history, let us know so we can add the information here.
Laser Displays Inc.
Laserium
Patrick Murphy (pre-Pangolin)
Laserist List histories
Links to other lasershow history websites