Toward the end of 1977, Donna Summer had released five albums in two years. All sold gold. In that brief period, she’d come a long way from her debut single, 1975’s “Love to Love You Baby,” a porn-on-wax steamer featuring Donna moaning and groaning for 17 minutes. Although an era-defining smash, the single (and album) gave little indication of the artist's vocal and songwriting talent.

In November 1977, the Boston superstar released her first double-LP, the grand concept disco album, Once Upon a Time. Donna and her collaborators, Pete Bellotte and Giorgio Moroder, crafted a suite of songs based on the story of Cinderella. Granted, the concept idea may veer toward trite. But the music is anything but.

Donna was about a year away from releasing the biggest hits of her career and the decade, including “MacArthur Park,” “Hot Stuff” and “Bad Girls.” With Once Upon a Time, she cemented her reputation as one of the most creative artists to emerge in the disco era. But it’s probably one of her most overlooked albums.

I Remember Yesterday, the forgettable LP that preceded Once Upon a Time, spawned the ground-breaking hit, “I Feel Love.” Noted for its artful and hypnotic use of synthesizers, the single paved the way for all styles of electronic music that jelled more than 30 years after it scaled the Top 10. Donna, Pete and Giorgio extended the imaginative synths on Once Upon a Time, adding an attractive metallic sheen to pulsating tracks like “Now I Need You” and “Working the Midnight Shift.”

Ever the vocal chameleon, Donna changed the color and texture of her voice to fit the character of the 16 tracks that sprawled across the four LP sides. She remembered her time in musical theater for the slightly kitschy melodrama of “Faster and Faster,” fanned the flames of her childhood gospel fire on “A Man Like You,” and flashed the sharp edge of her voice on “Rumour Has It.”

I never owned the album on vinyl, only on compact disc. But even as it plays continuously, I can tell where the breaks are supposed to be. The album is perhaps best experienced on compact disc – not only for the remastered sound, but because of the rainbow flow of the record. Having to get up to flip and change LPs may interrupt the experience too much.

The music finely mixes grand and lush arrangements, sweetened with just the right amount strings, with progressive, glinting synthesizers. Parts of the album transport you to a glitzy club in 1977, while others rocket you into today and beyond.

Once Upon a Time yielded one moderate hit, the charming “I Love You.” Because Donna was disco’s undisputed queen, cuts from the album received regular spins in the clubs, especially “Rumour Has It.” Once Upon a Time peaked at No. 13 on the pop charts and went gold.

The album’s theme reflected Donna’s life story, in a way. She had grown up poor and awkward in the Dorchester section of Boston. By 1977, at age 29, she had become one of the richest and sexiest female artists in pop. Her fairytale came true.