The Carpenters, a brother-sister duo known for cheery pop tunes and for love songs overflowing with sweet sentiments, came to prominence during one of the most tumultuous eras in the U.S. both musically and politically. In the wake of the Summer of Love, Woodstock, and the escalation of the war in Vietnam, Karen Carpenter's voice and Richard Carpenter's lush musical arrangements—described by detractors as "saccharine" and championed by others as distinctly smooth and easy on the ears—began to dominate the airwaves at the start of the 1970s. Their breakthrough hit, "(They Long to Be) Close to You" (1970), was penned by Burt Bacharach and Hal David, and released nearly a decade earlier by Dionne Warwick to little fanfare. But with Richard's lilting new piano arrangements foregrounding Karen's inimitable alto, the song shot to the top of the charts.

The Carpenters' follow-up single, "We've Only Just Begun," doubled down on the duo's melodic balladry with overdubbed harmonies, thus heralding a new age of innocence, or at least a softness in popular music that would vie with "the hard" (in the form of Janis Joplin, Led Zeppelin, and the Rolling Stones, among many others) for America's ears—and wallets. With their string of hits between 1970 and 1972, like "Rainy Days and Mondays," "Superstar," and "Top of the World," the Carpenters quickly developed a reputation for being squares, or as one critic put it, "goody four-shoes."

Both Richard and Karen chafed at what the infamous rock critic Lester Bangs called their "creepy" wholesomeness. The two complained about how A&M records marketed the siblings in soft-focus, vaguely romantic poses amongst jutting rocks on picturesque seashores. Meanwhile, John Bettis, Richard's lyricist and songwriting partner, unabashedly declared that in 1970, the year the Carpenters first topped the charts: "Everybody was dying to be something they weren't…Everybody was dying to not be from the suburbs. The fact of the matter was that we were who we were, and we were white, middle-class American kids. And we wrote like that, sang like that; we dressed like that; we lived like that."

By 1972, however, the Carpenters would come to defy expectations and innovate the easy listening format with something no one had ever heard before: a distorted rock guitar solo smack in the middle of a love ballad. "Goodbye to Love," one of the first bona fide hits composed by Richard Carpenter and John Bettis, introduced the world to that greatest of musical oxymorons: soft rock. It was Richard who requested the "fuzz guitar," the fly in the ointment of their otherwise familiar, tender approach to pop laced with oboes. Karen was the one who made the phone call to guitarist Tony Peluso, asking him to play for the track. As he recalls, "Richard wanted an aggressive, sawtooth guitar solo in the middle of this Doris Day easy-listening-style record." "Goodbye to Love" elicited a double take, upending expectations of the Carpenters and their music and disturbing some of their older fans who were concerned they'd gone over to the dark side.

By the middle of the decade, the Carpenters were on the waning end of what Neil Tennant of the Pet Shop Boys cannily described as an act's "imperial phase," or a performer's commercial and cultural peak. From 1970 to 1975, the Carpenters logged 12 Top 10 hits, including three No. 1 and five No. 2 singles, in addition to 14 gold records. After 1975, only one of their songs would ever reach the Billboard Top 20, let alone approach the Top 10. Karen and Richard both felt that their straight-laced image prevented the rock cognoscenti from taking them seriously as musicians. Far from being straightlaced in their personal lives, however, each of the Carpenter siblings was struggling with severe health issues by decade's end. Richard went to rehab for a Quaalude addiction, and Karen sought counseling for her struggle with anorexia as the 1970s drew to a close.

On February 4, 1983, Karen Carpenter died at the age of 32 in the same bedroom she grew up in, in her parents' suburban home nestled in Downey, California. Unlike many other young icons of rock and pop lost to overdoses under dramatic circumstances—from Janis Joplin to Jimi Hendrix—Karen died from complications as a result of her anorexia. She in essence faded out slowly, just like the music she and her brother Richard were known for making together.

Nevertheless, the Carpenters' musical legacy, largely owed to the singularity of Karen's voice, has attained a robust afterlife in decades since, through cover albums, reissues, and through tribute performances like Justin Vivian Bond's. Resonating in other voices, Karen's own haunts us with the enduring hope and yearning that suffuses so many of the Carpenters' songs, allowing both the squares and misfits who have grown to love them to hold onto the notion that "every sha la la la, every whoah-whoah-oh still shines."

Karen Tongson is Associate Professor of English, Gender Studies, and American Studies and Ethnicity at the University of Southern California. She is the author of Relocations: Queer Suburban Imaginaries (NYU Press), and the forthcoming Why Karen Carpenter Matters (ForeEdge Press). You can also hear Karen talk about pop culture, the arts, and entertainment on the weekly Pop Rocket Podcast, hosted by comedian Guy Branum.