From Rolling Stone:
This disco hit about a Big Easy streetwalker is still in rotation nearly thirty years after it hit Number One. The group was from Philadelphia, but the nasty groove was classic New Orleans, with producer Toussaint and his house band, legendary R&B stalwarts the Meters, funking up the beat. Thanks to the three ladies of LaBelle, every disco fan now knows at least one line of French: “Voulez-vous coucher avec moi?“
Recorded with lead singer Patti LaBelle and accompanied with backing from bandmates Nona Hendryx and Sarah Dash, it tells the story of a Creole woman known only as “Lady Marmalade”, who seduces a man she met on the street in New Orleans, Louisiana. Although the man has moved on from the experience, his memories of their tryst remain vivid when he tries to sleep. The song’s chorus, “Voulez-vous coucher avec moi (ce soir)?“, means “Do you want to sleep with me (tonight)?” in French, an unsubtle invitation to sexual intercourse. The same line appeared previously in the play A Streetcar Named Desire, coming from the promiscuous Blanche DuBois.
From Rolling Stone, reviewing the album:
With Patti LaBelle’s strident, nasal bellow in the lead, the band had always dealt in sassy, loose-limbed structures; the three women’s voices rolled over one another in waves. On Nightbirds, producer Allen Toussaint modernized this ferocious free-for-all with an almost mechanical underpinning of robot funk and juke-joint piano janglings. “Lady Marmalade” bursts off the first side with monstrous power. A disco staple today, it’s actually slower and harder than a classic 4/4 dance number, full of sinister rhythmic spaces in which the singers roar and tumble. No sad-hooker stories for these ladies – it’s Marmalade who’s having all the fun, while her enchanted john is left tormented by the encounter.
The band broke loose from the decorous girl-group tradition on Nightbirds and redefined sexual relations using the terms of R&B and its debt to gospel as metaphors for a larger cultural move. […] By 1974, black had been beautiful for almost a decade; the astrofunk goddesses of Labelle made it chic.