The root of the word "fan" is fanatic, and that certainly applies to some music lovers, particularly the extreme admirers of certain bands or types of rock music. Some people live for the music they love, and in the case of certain bands, there are enormous fandoms and cultures for the more extreme among their ranks.

To those of us who aren't fans of a particular band or musical style, such extreme fans might seem a little crazy, or even scary. Let's take a look at some of them.

5. Deadheads and Jam-Band Fanatics One of the first and most developed band-specific subcultures to appear was the extreme fans of the Grateful Dead, the "Deadheads." Somehow that fan culture survived and thrived for decades -- into the present -- and for fans of the band, the Deadhead phenomenon provided a sense of community. But for people who weren't hardcore Grateful Dead fans, the whole thing could look pretty dumb.

I was never a fan of Jerry Garcia and the boys, but tagged along to a Grateful Dead show at the Summit when the band was supporting the mainstream success of the "Touch of Grey" single. That show still ranks as one of the worst concerts I ever saw and one of the few times I really just wanted to leave one out of sheer boredom. I would have, too, except I didn't drive to the show. Observing the antics of the large number of Deadheads who had traveled to the show in some sort of filthy, pseudo-hippie caravan was enough to make me dislike that subculture forever.

When the Dead finally dissolved upon Garcia's death, other jam bands began picking up the slack, offering fans of this musical style and its cultural attachments to continue forward in a haze of pot smoke, patchouli and body hair, traveling around the country to see bands like Phish and others play their shows.

Pros: Jam-band fanatics are mostly harmless and easily avoidable if you stay away from certain shows. Cons: They're like hippies, but somehow even more irritating, proving the almost impossible is possible if you drop enough acid. The music is also largely boring. Danger Level: Probably nonexistent unless you're badly allergic to rambling hippie speak or get slammed into by someone dancing like a fool.

4. Members of the KISS Army Or whatever the mostly middle-aged über-fans of lame clown-rock band KISS are calling themselves these days

The thing is, KISS wasn't really taken very seriously as a musical group back in the '70s. Despite some good early albums of simple hard rock, the band never really got the type of musical acclaim that bands like, say, Derek and the Dominos or Yes got from critics and many older rock fans at the time. Turns out that it was hard for a lot of people to take a band seriously when they wore full face paint and outlandish costumes.

But their timing was nearly perfect, because a younger generation of rock fans was coming of age, and the over-the-top image of the band proved marketable even to children, in much the same way superheroes were. Images of KISS were plastered on everything from toys to garbage pails, and kids loved them. Fast-forward almost 40 years, skipping through the mostly embarrassing non-makeup era, and KISS decided to host a reunion of the original lineup in full makeup and regalia. I still remember the collective joy among rock fans in their late twenties to late thirties. We were finally going to get to see the "real" KISS either for the first time or for the first time in almost two decades.

And we see how that worked out. Gene "Money Vampire" Simmons and partner in crime Paul "Melting Starchild" Stanley continued on in a new era for the band, basically squeezing as much play out of the band's original image and back catalog as possible. This continued even after Ace Frehley and Peter Criss again left the band, replaced by two guys who wear their outfits and makeup onstage. It's all pretty weird when one thinks about it, but what's weirder to someone who's not an enormous fan of the band are the incredibly devoted KISS fanatics, most of whom are well into middle age by now.

KISS shows have always been about spectacle, but there's something inexplicably odd about seeing a 50-year-old accountant slather on an approximation of Ace Frehley's face paint to join his buddies at a KISS concert. They have conventions, and theme cruises. For some, the KISS fandom has become a total lifestyle, including filling their homes with KISS merchandise or deciding to be buried in a "KISS Kasket" when they finally Rock and Roll Over for the last time.

Pros: These people are mostly harmless, middle-class folks who really love KISS. Cons: These people are mostly harmless, middle-class folks who really love KISS. Danger Level: Basically nonexistent, except for the irritation that may occur if they accidentally drip makeup all over you.

3. Rush Fans Canadian rock trio Rush is an oddity in rock history. Somehow they managed to attract standard rock and metal fans along with lots of nerdier types who also found something to love about the band. Combining virtuoso playing and complex musical compositions that cover diverse material ranging from Dungeons and Dragons-style fantasy and science fiction to a variety of philosophical subject matter, the band has forged one of the strangest and most dedicated fan bases in rock and roll.

I remember in the very early '80s, Rush still seemed to have a slight danger about them. Their fans seemed mostly to be the same types of hard-rock dirtbags who sold weed to junior-high kids and drove Camaros around town, but over the years that appeared to change a lot. The last time I was at a Rush concert, it looked like half the people in attendance probably owned a small software company somewhere, and a lot of them had brought their kids.

So why include Rush fans on a list like this? Because Rush is one of the most polarizing major bands in the world. People seem to either love Rush or hate them, with very little middle ground. Explaining the appeal to a non-fan is almost as futile as trying to convince someone that water isn't wet. People seem to universally agree that Rush are great musicians, but the folks who like them tend to love them, and everyone else tends to dislike them a lot. Rush is often characterized as the world's biggest cult band, and hardcore fans even have their own convention they can attend.

Pros: Fans might be able to help you fix your computer when it crashes. Cons: They might also launch into a lengthy discussion defending Geddy Lee's voice. Danger Level: Essentially nonexistent, unless you're threatened by people who play Dungeons and Dragons or work in the IT Department.

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