“While we were performing together onstage once, Mr. Ohtaki asked me, ‘Why are you singing in such a weird way?’” recalled Mr. Suzuki, who proudly wore a Devo T-shirt. “I replied, ‘I’m just imitating you.’”

Happy End transformed the rock scene with poetic Japanese lyrics that somehow fit the cadence and rhythms of American-style rock. The band’s 1971 album “Kazemachi Roman,” a classic of the genre, describes with a shrug how the Tokyo of their childhood was being swept away and replaced by a high-tech metropolis. The song “Natsu Nandesu (It’s Summer),” with echoes of Neil Young, is a wistful idyll darkened by storm clouds and a disaffected narrator: “I’m so bored, I twirl a parasol.”

Mr. Endo’s “Curry Rice” shows how some songs wedged political hot topics into scenes of everyday life. The aroma of curry on the stove fills a small apartment while the TV carries a news report about the death of Yukio Mishima, a literary star who shocked the nation by staging a failed coup and committing ritual suicide. The juxtaposition of death and hunger Mr. Endo felt in that moment, he explained, led to a “mysterious” feeling and then to an understanding of “what it means to be human.” (On Oct. 25, after this article had gone to press, Mr. Endo died at age 70. According to a note on his website, he had been suffering from stomach cancer.)

On other tracks, Takuro Yoshida, from Hiroshima, plays a sunny, fast-picking tune that could almost be by Crosby, Stills & Nash. Tetsuo Saito, the “singing philosopher,” sounds like the wild man in the meditation room as he cries in Japanese: “We strip off the masks and expose all truths of society.” (Years later, Mr. Saito had a huge pop hit that began as a Minolta TV jingle.)

As Michael K. Bourdaghs, a professor of Japanese literature and culture at the University of Chicago, explained in his book “Sayonara Amerika, Sayonara Nippon: A Geopolitical Prehistory of J-Pop,” Happy End’s embrace of Western rock led to a kind of identity crisis: What of this music was Japanese, and what was American?