The title refers to an ancient philosophical concept that regards proportions in the movements of celestial bodies (the Sun, Moon, and planets) and formed the basis for ancient astronomy.
At the end of the episode Dr. Taylor, played by Howard Hesseman, says "I'll never forget the 60's; *that* was music." Hesseman played Dr. Johnny Fever, a radio DJ, on WKRP in Cincinnati (1978).
To Devon's irritation, Vic's nickname for him is "Doogie" after the title character in Doogie Howser, M.D. (1989). Neil Patrick Harris, who played Doogie Howser, also played Howie Morrison in From Within (1996).