Geek Rockin' It
He's the least-known musician that you deserve to know. His name is Jonathan Coulton (and his website is Jonathan Coulton dot com) and he is a geek rocker.
Yes, a geek rocker. What does that mean, you ask? It means that he is a geek who makes music. And he has quite a following though he doesn't get a lot of publicity. But his following is what one might consider a subculture. They are mostly people who are geeks or nerds, often tech people or science fiction fans (or both) because he writes for them.
I'll give you an example of a geek rock song: "I'm Your Moon," in which one of recently-deplanet-ed Pluto's moons sings to the planet. Or how about "The Future Soon" in which he sings "'cause it's gonna be the future soon/and I won't always be this way/when the things that make me weak and strange/get engineered away." Or "Code Monkey" about the computer programmer who gets tired of being jerked around by his boss and just wants to live his own happy life. Or "Re: Your Brains" about the zombie who wants to make a zombie of his coworkers and attempts to convince them to be bitten.
It's underground, the culture of the most intelligent people that you never paid attention to. It's music that celebrates that segment of the population; one that is often ignored.
Jonathan Coulton often plays live with comedy music duo Paul & Storm (paul and storm dot com). I went to a show a few months ago, and had the time of my life. I was there until 1 AM helping them to clean up after the show and separate the stuffed animals from the money that had been attached to them and thrown from the stage.