Bad Girls marked the high-water mark in Donna Summer's career, spending six weeks at Number One, going double platinum, and spinning off four Top 40 singles, including the chart-topping title song and "Hot Stuff," which sold two million copies each, and the million-selling, Number Two hit "Dim All the Lights." Producers Giorgio Moroder and Pete Bellotte recognized that disco was going in different directions by the late '70s, and they gave the leadoff one-two punch of "Hot Stuff" and "Bad Girls" a rock edge derived from new wave. The two-LP set was divided into four musically consistent sides, with the rocksteady beat of the first side giving way to a more traditional disco sound on the second side, followed by a third side of ballads, and a fourth side with a more electronic, synthesizer-driven sound that recalled Summer's 1977 hit "I Feel Love." Though remembered for its hits, the album had depth and consistency, concluding with "Sunset People," one of Summer's best album-only tracks. The result was the artistic and commercial peak of her career and, arguably, of disco itself.
AllMusic Review by William Ruhlmann