“The Vanguards” is a humorous, nostalgic, and well-researched trek through the various avant-garde generations of the 20th century; that is, the “Lost Generation” with the Flappers and Bohemians, the “Beat Generation” with the Beatniks, the “Now Generation” and the Hippies, and the “Blank Generation” and the Punks. The four central characters are women from these succeeding generations. They’re joined by several male characters who are absolutely critical to the plot, but it’s still the women who carry the bulk of the...