Study the Floor Plan, Then Rave On With each room devoted to a different genre, would-be ravers may need some help telling house from hard-core.

When you file into your first rave party, the initial impression is chaos. The noise level is simply incredible. The crowd is overwhelming in size, packed together and dancing, most not even facing the stage.

But grab the flier that drew you here in the first place and you’ll discover an inkling of order. Above the DJ listings are names of music genres such as house, drum-and-bass, techno, breaks, trance and hard-core. Each one has a separate room at the venue. You begin to realize that a rave is like a theme park with different areas of sound to explore.

And each one draws a loyal tribe of followers who swear by their chosen subgenres. For the house-heads, breaks-fiends and hard-core candy ravers, identifying with one style of dance music over the others is an essential part of the experience.

But what about the uninitiated masses who still call all dance music “techno”? Ten years after its arrival, electronic dance music still remains a mystery to most when it comes to its many subdivisions. With that in mind, here’s a guide to the key genres, designed to direct you into the appropriate room with a groove.

House

House music always takes the prime real estate at a rave, and its adherents are usually the most eclectic mix of people. House is to dance music what Coca-Cola is to soda--the foundation for many of the offshoots that now define the boundaries of dance music.

Characterized by a steady, thumping beat provided by a kick drum, house started in the early ‘80s when club DJs--primarily in Chicago--were looking for a new, harder-edged sound after the disco trend wore out.

House wasn’t just a revolution in sound. It was also a cultural reaction to the glitzy, mainstream sensibilities of disco. The music aimed for a more underground, rebellious feel than that found in your typical “Saturday Night Fever” disco.

Today’s house stars include Daft Punk, Basement Jaxx and Armand Van Helden. Both Fatboy Slim’s and the Chemical Brothers’ most recent albums are considered throwbacks to classic house music.

Though house originated in dance clubs, it found a permanent home in the rave scene a decade ago in England, where it still thrives. The music has begotten a series of subgenres, such as acid house (recognizable by its high-pitched squeals or flatulent bass lines) and deep house (influenced by Latin and American jazz).

It also caught the ear of some of pop’s most stylish figures, including Madonna, whose 1990 single “Vogue” is a classic example of house. Her latest dance hit, “Music,” is influenced by the sound of French house iconic duo Daft Punk.

Expect a great deal of funkin’ and groovin’ in the house room. Its disco roots always provide a sexy time out dancing.

Preparation: Daft Punk’s “Homework” (Virgin), Dimitri From Paris’ compilation “A Night at the Playboy Mansion” (Astralwerks).

Techno

It can be hard to distinguish house from techno. While house tends to use traditional instruments such as horns and strings, a techno fan might be able to find the funkiness in the sound of a computer printer.

The history of techno goes back to Kraftwerk, the German synthesizer band best known for its “Autobahn” and “Trans Europe Express” albums in the 1970s. But much of the credit for contemporary techno goes to Detroit record producers Juan Atkins, Kevin Saunderson and Derrick May. They added a strong dance orientation to basic techno in the early ‘80s, inspired by the industrial culture of their city. Quite simply, techno is the sound of technology.

Artists such as Jeff Mills, Richie Hawtin, Aphex Twins and Carl Craig have pushed techno further with fearless experimentation. German producers helped inspire the techno-industrial crossover that led to bands such as Nitzer Ebb and even Nine Inch Nails.

Preparation: Derrick May’s “Innovator” (Transmat), Richie Hawtin’s “Decks, EFX & 909” (Nova Mute).

Drum-and-Bass

No other sound has developed as much since the birth of the rave, and no other genre entails as many idiosyncrasies among fans, from style of dress to slang. In North America, followers have attached themselves to the psyche of hip-hop. The mentality is dark, underground and outlaw.

Producer Goldie was perhaps the first to turn drum-and-bass (also known as jungle) from a homemade party sound rooted in the slums of London into an almost cerebral form of music. Today, artists such as Roni Size/Reprazent have fused elements of jazz, hip-hop and techno into a sophisticated style that suits both the dance floor and the bedroom. The essence of jungle lies in the bass sounds and the complexity of the beats. Think of hip-hop beats sped up several times, creating a sort of hyper-funk.

A jungle room is always the most physically active spot at a rave. You should feel the rumble of the bass in your stomach, so you can appreciate the style fully only when you hear it full blast. That’s the only way to pick up on its subtleties. Or is it the lack of subtlety?

Preparation: Roni Size/Reprazent’s “New Forms” (Talkin’ Loud/Mercury), Goldie’s “Timeless” (WEA/London/Sire).

Breaks

Big beat, as this style of breakbeat, or breaks music is known, was a short-lived fad in England that began around 1996. Big beat quickly became oversaturated and is now considered unfashionable. Some of its early champions, including the Prodigy, the Chemical Brothers and Fatboy Slim, have changed their sound somewhat by reverting to house music.

For many in America, however, big beat is the most accessible form of dance music. Its marriage of rock ‘n’ roll riffs and hip-hop beats is used everywhere from car commercials to sports television promos. The breaks room attracts the more seasoned raver and the party’s better dancers. With beats reminiscent of early-’90s hip-hop and lots of record-scratching, the sound demands high energy from its audience. There’s really nothing serious about breaks, but its stars--Uberzone, DJ Icey, Simply Jeff--are synonymous with the American rave circuit.

Preparation: Fatboy Slim’s “Better Living Through Chemistry” (Skint), the Chemical Brothers’ “Live at the Social” (Heavenly).

Trance

House music with a heavy dose of drama. Everyone looks serious when dancing to trance and its darker cousin, progressive house. With its pseudo-spirituality and consistent beat, it has become one of dance music’s dominant styles.

L.A.-based BT epitomizes epic trance, which sometimes incorporates sounds such as birds chirping and waves crashing. But these days most trance has a progressive house edge, using louder bass lines and moody keyboard stabs.

Trance used to bring out the psychedelic element of the dance-music crowd at a rave. But more of its practitioners are catering to yuppie tastes, allowing super-DJs such as Paul Oakenfold and Sasha & John Digweed to service ultra-hip clubs that pack in thousands of revelers each weekend.

Preparation: Sasha & John Digweed’s “Northern Exposure” (Ultra), Paul Oakenfold’s “New York” (Boxed).

Hard-core

Some dance purists like to forget hard-core exists. It’s the fringe offshoot of an already fringe style of music. House and techno music usually offer 125 beats per minute. Hard-core can reach speeds of 300 bpm.

Teenagers are the main audience for hard-core, whose splinters range from the dark and relentless speedcore to the cartoonish happy hard-core (add a kick drum to the latter and you have the sub-subgenre known as gabber or Rotterdam). You’ll find the most outlandish costumes in the happy hard-core room--kids with Mickey Mouse hands, gas masks, cow-pattern fur. Producers will sample everything from Britney Spears to classical music. As long as you can speed it up.

Preparation: Ron D Core’s “Decibels of Destruction” (Strictly Hype), various artists’ “Happy 2b Hardcore” (Moonshine). *