"I always try to write songs so that they could be read on lots of different levels, so you could appreciate them superficially and then if you go deeper you could see something else," Madonna told British TV's Jonathan Ross in 1992, promoting her Erotica album and Sex book. This was the puffing of a now frequently bared chest or maybe autofellatio from a woman who had recently told Vanity Fair, "I think I have a dick in my brain."

The material she was talking about, which included a jazzy hip-hop ballad that used the "eating out" double entendre to make cunnilingus sound like fine dining and a song called "Why's It So Hard," in which the "it" was not a penis, didn't exactly require trained dogs to sniff out its multiple tiers. And yet, like the works she was discussing, her self-flattery was utterly justified in its exaggeration.

Today, Erotica turns 20 (tomorrow Sex will do the same), but only now has S&M really broken the mainstream pop culture to the level of a phenomenon (courtesy of 50 Shades of Grey). Only now are we accustomed to having a pack of female pop icons who sing about being excited by whips and chains, who snarl, "I'm a slut like you!," who espouse the virtues of "pussy power" on talk shows. Only now are we used to the kind of content onslaught that Madonna delivered in 1992, not only via (almost) simultaneous multiple media but by having those songs and images and words that made up said media hit multiple buttons at once, themselves. It may not seem like it, but as an audience, our appreciation of things has only gotten more nuanced as time has gone on. We like levels. We are in a time when a song can become a pop cultural force by being awful, when the repellant attracts reality TV viewers, when mocking is a form of appreciation.

If Erotica wasn't responsible for these developments, it certainly predicted them. The album was more ahead of its time than any pop record released that year.

Recorded between October 1991 and September 1992, Erotica found Madonna reteamed with Andre Betts and Shep Pettibone, her co-producers that were separately responsible for the two tracks recorded specifically for 1990's Immaculate Collection hits compilation – Betts' Public Enemy-sampling "Justify My Love" and Pettibone's giant house number "Rescue Me." At its most basic, Erotica further explores the paths of those very different songs. They are yin and yang as dance music goes, but they share themes of the intermingling of love, power and sex.

"Justify My Love" was a multimedia phenomenon itself, thanks to its MTV-banned video. It's one of the strangest songs ever to hit No. 1 on the Billboard Hot 100, a heavy-bottomed hip-hop track that Madonna moans and mutters through, singing only when she hits the chorus. That it got the airplay it did with its mostly spoken foundation, unsettling mood and porno undertones says everything about Madonna's command on entertainment at that point. She monetized controversy while creating something that both responded to and operated unlike the pop culture of its day. During her 1983 American Bandstand appearance, Dick Clark asked Madonna what her dreams were for the rest of her career and she told him, "To rule the world." By 1990, she was as close to doing so as a pop star could get.

Power begat power. An emboldened Madonna established her own company, Maverick, achieved total creative control and let her own mouth go wherever it wanted by releasing Erotica and Sex as its first two projects. In Pettibone's brief but anecdote-filled Erotica Diaries, Madonna comes off as impatient and assertive, as domineering in the studio as her dominatrix character Dita was on wax. Even when Erotica was praised (and despite its reputation as a maligned work, the album was largely praised by critics), people used words like "cold" and "calculating" to describe the album, as if honesty is inherently spontaneous, as if icy isn't hot, as if virtually every album that came out before Erotica and since weren't calculated in some way. If nothing else, Madonna's open provocation was a full disclosure of her intentions, a pulling back of the curtain on the process of creating music that owes its existence to listener response. It's a type of pure expression on a dirty album.

Over 10 years later, Madonna would reflect on the project by saying, "I was interested in pushing buttons and being rebellious and being mischievous and trying to bend the rules." At the time, though, she told Steve Blame, "The most important thing is that I feel fulfilled as an artist." Negotiating the needs of the many and the needs of the self is exhausting as marathon group sex, and in this respect, Erotica failed. It sold about half as many copies in the U.S. as the non-soundtrack album that preceded it, 1989's Like a Prayer (quadruple platinum versus Erotica's double). None of its singles were smashes, and "Bad Girl" marked the first time Madonna missed Billboard Hot 100's Top 20 since 1983's "Burning Up."

Erotica is moany and moody. When it is sugary, it's campily so ("Bye Bye Baby"). It doesn't have pop's polite sheen and Madonna's nasal vocals nag. It came with hype, an endless string of interviews during which Madonna looked confrontational in her style, with a gold tooth, cropped hair and often drugged-out eye makeup. A book accompanied the album's release. Both played with sensibilities, treating sex as a dark sacrament or lighthearted comedy, depending on the moment.

It was so much for people to take in. Too much. The only songs to really make a dent into U.S. radio, "Deeper and Deeper" and "Rain," were the album's most straightforward offerings. We weren't used to the level of noise we'd soon learn to process (see: the block waveforms of Lady Gaga's over-stuffed sound and her endlessly shifting public persona — she doesn't have eras, she has moments). We weren't yet comfortable enough with attention-grabbing to value it — it would take years before that kind of behavior became commonplace on a citizen level. Internet would make it virtually mandatory for those interested in fostering a voice.

Erotica today maintains most of its put-on grit (most of the vocal takes are the demos). The crunch-and-pump house sounds visceral, the hip-hop soul sounds brutally elegant, the sometimes crooning, sometimes spoken vocals sound like versatile performances, as opposed to desperate attempts at carrying a tune. The booming and minimal Erotica sounds triumphantly in charge of itself. All that calculation makes for songs that do exactly what they set out to do.

"I don't think it's so unusual, the ideas I presented. What's unusual is I talk about it," Madonna said to Australia's 60 Minutes at the time. Indeed, pop stars just didn't reveal like she revealed. And even more unusual were her tones – her tongue-in-cheek (or wherever) handling of cunnilingus ("Colonel Sanders says it best: ‘Finger lickin' good!'"), her presentation of S&M as simultaneously serious and absurd (she goes down on a boxing puppet in the "Erotica" video), her frequent intersecting of sex and love ("Erotica…romance," are the first words you hear on the album).

Sex boasts even more layers and is more engaging for it. There are straightforward jokes amidst the softcore porn, which includes depictions of water sports, bondage, pansexuality amongst both sexes and public nudity. "How do you give a good blow job?" reads text over a shot of Madonna sitting spread-eagle poolside as Naomi Campbell grins into her crotch; "Drink a lot of beer first" it says on the next page, as Big Daddy Kane looks on, his hand on Campbell's ass. However, the book operates best in the sticky realm of intention-ambiguity – regardless of what she meant when she wrote its text, Madonna's bluntness has a comedic thwack. All of these sentences start mini-essays: "Sex with the young can be fun if you're in the mood"; "There's no better way to wake up in the morning than with my lover's cock inside of me"; "When I was a child I used to sit on the toilet backward and wait for the burning sensation between my legs to go away."; "I like my pussy."

That last one ends, hilariously, with:

Sometimes I stick my finger in my pussy and wiggle it around the dark wetness and feel what a cock or a tongue must feel when I'm sitting on it. I pull my finger out and I always taste it and smell it. It's hard to describe it smells like a baby to me fresh and full of life. I love my pussy, it is the complete summation of my mlife. It's the place where all the most painful things have happened. But it has given me indescribable pleasure. My pussy is the temple of learning.

As "Dita," she writes long letters to "Johnny," about their shared lover "Ingrid." In one, she goes on and on about the wetness of Ingrid's pussy and then ends the letter with "P.S. Are you hard yet?" In a one-page story, she chronicles her affair with a Puerto Rican kid who had "hardly any pubic hair." She claims to think she devirginized him and yet he inexplicably ends up giving her crabs. "So you win some you lose some," she concludes. Har, har?

[There was a video here]

A lot of the reviews got it (the Times accounted very well for the messages' complexity), some interviewers really didn't: the interviewer on Australian 60 Minutes told Madonna that her depiction of masturbation "just strikes me as horrible." She took it in stride, sharing cardinal wisdom that anyone who dares to talk about sex in public quickly comes to understand: "I think that people's reaction to specific situations in the book was much of a reflection of that person than me."

No one is under any obligation to look at the Rorschach you present, though. Erotica's rejection must have been irritating to experience firsthand but that is the risk you take when you lay your bare self out there. "And I'm not sorry," Madonna told us on the follow-up to Erotica, 1994's Bedtime Stories. Within context of the album, the song urged listeners not to get it twisted – she wasn't rescinding anything expressed on her last album just because her current one was way gentler and less explicit. Understood, but the song nonetheless comes off as whiny. "You punished me for telling you my fantasies / I'm breakin' all the rules I didn't make," starts the second verse. But no one actually punished Madonna for sharing her fantasies — they just responded negatively and didn't buy as many copies of her album as they did last time around. It was a light spanking that she recovered from quickly (though she'd still have to make it through being a laughingstock all over again in the universally panned Body of Evidence, which came out in January of 1993). Her live translation of the Erotica era, The Girlie Show tour, was a well-reviewed hit. Stories' "Take a Bow" ended up being the longest running U.S. No. 1 of her career. In the years that followed, she remained relevant even if her music isn't as much of a sure-bet as it once was. Madonna is doing just fine.

If anything, the relative flop status of Erotica shaded in her career — it was a bold, dark moment that proved a superstar was indeed capable of miscalculating public taste, of missing the mark of mass appeal. For a moment, Madonna appeared to be vulnerable and more human than even what her soul- or flesh-baring suggested. She smacked the world with her whip, and it smacked back harder, delivering some sadism to complement the masochism inherent in sharing her sadistic tendencies with the world.

P.S. Are you hard yet?