"The Shape of Things to Come", written by Barry Mann and Cynthia Weil, was a #22 chart hit for Max Frost and the Troopers (a "studio group", made up of session musicians) in 1968. In 2006, it was featured in commercials for Target Stores.
American International Pictures originally offered the role of Max Frost to noted folk singer-songwriter Phil Ochs, who was known at the time to want to branch out into film work. However, after reading the screenplay, Ochs rejected it, stating the story presented the youth counterculture of the 1960s in a badly distorted light.
Max Frost (Christopher Jones) asks Billy Cage (Kevin Coughlin) how long he thinks he is going to live and he replies "30, man." Coughlin was later killed in a hit-and-run accident on January 19, 1976, only five weeks after his 30th birthday.
The trivia item below may give away important plot points.
On November 5, 1968, the Republican nominee Max Frost (a.k.a. Max Flatow) is elected President of the United States, defeating the Democratic incumbent Lyndon B. Johnson. He is inaugurated as the 37th President on January 20, 1969. In reality, former Republican Vice President Richard Nixon won the 1968 election, defeating the Democratic incumbent Vice President Hubert H. Humphrey. At the time that Wild in the Streets (1968) was filmed, it was widely expected that Johnson would run for a second full term in 1968. However, on March 31, 1968, he announced that he did not intend to do so.