This tape is a compilation of different content:

00:00-19:49. Part of a Buckminster Fuller documentary. Perhaps Richard Snyder’s “The World of Buckminster Fuller” (1974) It’s taped in color, which didn’t start at SCI-Arc until 1980.
19:58-42:18. A lecture by Glen Small.
30:16-33:07. No audio.
33:08-33:35. Audio briefly returns, then drops out again until a few moments in the last two minutes of the tape.
37:05-37:51. Performance in SCI-Arc’s main space. Ken Kellogg (?) and others march out of the Main Space with flowers behind a motorcycle through the audience.
37:52-42:18. More of Glen Small’s lecture.
42:19-49:13. Archival footage of Glen Small lecturing, being interviewed by Eric Chavkin, stills.