Many of the most explosive and virulent online videos — think: "Star Wars Kid," "Numa Numa" and the recent interpretation of "Thriller" by Filipino prisoners — manage to be at once bizarre, hypnotic and borderline upsetting. Tay Zonday's new hit YouTube song, "Chocolate Rain," is no exception.

"Chocolate raiiiiiin," belts Zonday again and again, in a voice so cavernously deep that it couldn't possibly be coming from the skinny, sweet-faced boy on the screen (he's actually 25). "Some stay dry and others feel the pain. Chocolate raaaiiiin."

Helping this refrain to super-glue itself into your mind is the short, looping piano phrase that is the song's musical backbone. The riff is replayed, with minor variations, something like 50 times — the same number that Zonday chants "Chocolate rain."

But the video's most unforgettable element, and perhaps its viral tipping point, is the message that flashes across the screen during the first minute: "I move away from the mic to breathe in."

True to his word, Zonday jerks his head back every 10 seconds for the rest of the song.

As the initial puzzlement wears off and you begin to listen to the lyrics, you quickly become aware of "Chocolate Rain's" central contradiction: Hold on a second — "some stay dry and others feel the pain"? This is a song about racism. But ... racism is not funny. But "Chocolate Rain" is funny ... or ... maybe it's not. But isn't it?

Either way, "Chocolate Rain" has become a force of nature. The video has earned more than 4 million YouTube views and is close to breaking into the YouTube music category's top 100 of all time. When it does so, "Chocolate Rain" will be one of only a handful of self-produced songs on the list — and the only one that's not an instrumental.

Yet there are even better measures of "Chocolate Rain's" reverberations around the Net. Not only do its 50,000 comments make it YouTube's ninth-most-discussed video ever, but "Chocolate Rain" has spawned such a tidal wave of remixes, riffs, covers, mash-ups, cartoons and spoofs that only "Numa Numa" and "Star Wars Kid" may have more imitators.

Nor is Zonday a one-hit wonder. All 17 of his YouTube videos have achieved success. His karaoke version of Rick Astley's 1987 pop hit "Never Gonna Give You Up" has scored 825,000 hits. In "Canon in Z," Zonday, clearly a skilled pianist, performs an original arrangement of Pachelbel's Canon (100,000 hits). Even a video of Zonday reading sonorously from Tim O'Brien's "The Things They Carried" has drawn 130,000 views.

Of course, it doesn't hurt to get a little help from YouTube. The site's editors have featured several of Zonday's recent videos on their home page, where a video can get tens of thousands of hits in an hour.

It's not hard to understand YouTube's interest in promoting "Chocolate Rain" or Zonday. Though both video and artist are a little wacky and chuckle-inspiring, they are fundamentally unlike "Star Wars Kid" or "Numa Numa" — which draw heavily on the freak factor. Zonday is a talented musician who not only writes and produces original songs but also can shoot and edit them into videos.

The success of "Chocolate Rain," then, sends just the kind of message YouTube wants its users to get: You don't have to be Avril Lavigne, OK Go or My Chemical Romance to produce a video people want to see — anyone can do it.

Zonday himself is a believer in YouTube's potential to tap into a global pool of bedroom artists who might not be comfortable performing "in front of people." In the unconnected days, Zonday said, these musical introverts would have had to settle for "a life passion that's basically between them and a wall."

But with YouTube, "it's them, the wall and a camera. The camera becomes a way to be social with other people."

On the phone from Minneapolis, Zonday described himself as just such a person. He grew up in a strict household where his parents were "always relatively scared of pop culture" and he was "never really allowed to do things that a lot of people my age did." So he went to his room, "shut out the world," and taught himself to play.

Zonday, a Ph.D. candidate in American studies at the University of Minnesota, had trouble even naming his musical influences. "I feel like I have a very limited vocabulary in that regard," he said, adding, "but in some ways, I think that can be an asset."

Even many of Zonday's lampooners admire him. "One thing I am sure of is that Tay Zonday is something special," said Londoner Russ Houghton, 30, whose popular "Chocolate Rain" parody redubs the original with absurdist lyrics. ("Chocolate rain/ Before using your bicycle, always check your brakes"). "I'm a fan, and I think he's a star, even if it's for slightly ironic reasons."

Zonday is aware that "Chocolate Rain" didn't take off until "people started to engage it as humorous," as he put it, implying that it was not necessarily intended that way. He did, however, admit to its being "quirky."

"If 1 percent of people get a sense that it's about something deeper, you take that gain and move forward," said Zonday, who studies the relationship between performance and social movements. "If everyone else is just entertained, then that's that."