A diva who defined the disco moment Donna Summer poses for an album cover session on May 16, 1978, in Los Angeles. Mark Coleman: Donna Summer, who died Thursday, defined the disco era of the '70s He says her music first found audience in NYC's gay club scene, then gained national fame He says her "Love to Love You Baby" was a racy, controversial and influential hit Coleman: She developed as artist over years, but her disco hits are biggest legacy Editor's note: Mark Coleman is the author of "Playback: From the Victrola to MP3, 100 Years of Music Machines and Money (Da Capo) ." He wrote about Donna Summer in The New Rolling Stone Album Guide (CNN) -- Donna Summer defined the disco era. Her brazenly sexual hits "Love To Love You Baby" and "I Feel Love" horrified some and delighted many more when they came out. They also helped to propel disco into a national phenomenon. Even now, the sound of her voice -- controlled yet passionate -- summons up the hedonistic, willful spirit of the late 1970s. Summer died from cancer Thursday at 63. Her passing offers an opportunity to reconsider her musical contributions and the legacy of disco. The legacy of America's disco queen is lasting But she deserves more than nostalgic praise, because her records with producer Giorgio Moroder have had a lasting effect on pop music. Listen to Lady Gaga's "I Was Born That Way," for starters. Not only does the disco-inflected rhythm evoke Summer's dance tunes, but as a gay-pride anthem, it recalls the roiling, joyful setting in which Donna Summer's music first found its audience. Mark Coleman Disco originated in the 1970s New York club scene, and it was Summer's "Love To Love You Baby" and then the Bee Gees' "Saturday Night Fever" that catapulted it onto the national stage. In "Love To Love You Baby," a strong-voiced woman gives herself over to pure pleasure. This feeling of abandon reflected the spirit of the emerging gay liberation movement. Back then, the music and its culture was huge. But to be honest, these days Donna Summer -- and the disco craze she embodied -- sometimes get a bum rap. Disco is a kind of guilty pleasure for people of a certain age, a slightly embarrassing hangover from the simultaneously wild and innocent days of their youth. But they -- we -- have nothing to be ashamed of, and neither does Donna Summer. Because underneath the flashy exterior and dated trappings of the best disco records lurks true heart and soul. And disco records don't get better than the ones Donna Summer made with Moroder. "Love To Love You Baby," a Top 10 hit in 1976, largely consists of vocal moans and sighs over an orchestrated rhythm track. "At first it was startling, almost embarrassing -- even in this age of rampant pornography," wrote critic Albert Goldman in 1978. And Summer's sexy album covers fed into the disco diva persona. But she was no moonlighting fashion model. Born in Boston, she had performed in European productions of "Godspell" and "Hair" before she met Moroder in Germany. Moroder crafted a sleek musical background for her creamy vocals, cushioned by strings, synthesizers and a fluid dance beat. When the tingling "I Feel Love" hit the Top 10 in 1977, her sound became almost purely electronic. Perhaps this is the moment when the machines began to take over the music business. In reality, Donna Summer never conformed to the stereotype of disco singer as producer's plaything, despite Moroder's commanding presence. She was ambitious, releasing concept albums such as "A Love Trilogy" and "Four Seasons of Love" and an epic disco-fied version of "Macarthur Park," by 1960s songwriter Jimmy Webb. And at the end of the 1970s, Summer came into her own. The double album "Bad Girls" was her magnum opus. Even disco-hating rock fans were taken aback. "Bad Girls" added soaring lead guitar lines and more varied songwriting to the mix. The singles "Bad Girls" and "Hot Stuff" took this disco-rock fusion to the top of the pop charts, while the slow-dance "Dim All the Lights" revealed more of Donna Summer's personality than her earlier hits. Later in the '70s, Summer became a born-again Christian and began to distance herself ever so slightly from her sexy image. In the 1980s, America moved on from disco, and so did Summer. She dabbled in Las Vegas schmaltz, made an ambitious album with Quincy Jones and came bouncing back with the assertive "She Works Hard for the Money" at the dawn of the MTV era. She continued to record comeback albums well into the 1990s, but over the past decade or so, the new music came less frequently. She performed the occasional greatest hits tours after the disco craze had long since retreated. And her music gained hipster cachet, even fully divorced from the cultural flash of its time. Indeed, every synth-pop group from Depeche Mode on down owes Donna Summer a big thank you, if not a royalty check, for the influence and innovation of "I Feel Love." "Generally I don't think there is too much art involved in what I do," said Moroder in 1978 at the peak of his career. But I do know that I achieved something specially different with 'Love To Love You Baby' and 'I Feel Love.' These songs will endure. The opinions expressed in this commentary are solely those of Mark Coleman.