Listening to a few of Jonathan Coulton's songs in a row feels sort of like a Saturday afternoon spent hyperlinking from one Wikipedia page to the next. His collected tracks are a deeply addictive quagmire of trivia, an Internet-borne time suck of knowledge.

How do seahorses reproduce? What was the landmark policy during John Tyler's presidency? What do you call the leader of a curling team? All of these questions came into Coulton's head at one time or another and the answers were too good not to sing about.

A former computer programmer, Coulton first rose to fame in 2005 in tech and sci-fi circles. Since then, his humorous indie-flecked pop songs about things as complex as DNA and mundane as the SkyMall catalog have reached even more fans. Sure, a zombie-themed number called "Re: Your Brains" is one of his more popular hits. But he has managed to make a story about a brain-hungry office flack or even the history of lobster in America carry as much weight as the crisis of aging.

"Certainly I have written about Pluto, and zombies, and giant squids who are sad, and mad scientists, more so than, say, U2," said Coulton, who plays the Guthrie Theater on Monday. "But just like them, I'm writing songs that have characters and emotional content and tell stories, and sometimes I choose a mad scientist as my subject, and sometimes I choose a sad 42-year-old man as my subject -- and sometimes both."

Of his 10th album, the zombie-free "Artificial Heart," he said, "I think the nerdier stuff is definitely a little underrepresented. I've been looking around at my circle of friends and we're all having the same kind of 'Omigod, we're getting old' freakout. It's a thing that happens every decade when there's a zero at the end of your age, you start thinking about these deep subjects. Life is complicated and weird, so I think a lot of the songs on this album are about that."

The new songs may be a little less nerdy, but his method of distribution hasn't changed. Coulton sells all of his music on his website for $1 per track. His system is a byproduct of an overall trend in cultural consumption that he is seeing. He says he can't even remember the names of the books he's reading, because he's only reading them on his phone.

"It's a weird side effect that I'm sure is not going to make the publishers happy, but that's definitely the way the content has been moving," he said. "It's almost like content is being freed of its context. People don't know anymore what network their favorite shows are on. There is a general trend to just think about the song they're listening to and not think about what album it's on, what label it's on, sometimes even who the artist is."

That's all fine with Coulton. Without a label to answer to, he can make as much or as little music as he wants, and keep all of the profits. It's a system that works: In a 2011 interview on NPR's "Planet Money" he said his Internet sales bring in about $500,000 a year -- roughly the same gross income as the most recent winner of "American Idol." Not bad for a guy whose big break came when Popular Science declared him its "contributing troubadour," and whose music is more readily heard on the "Portal" video game series than on Top 40 radio.

That's not to say he's rich; without a label, he has to front his operating costs, and there's the added expense of living in New York City. "I would probably be a millionaire if I was living in any reasonable part of the country," said Coulton. "I would live like a king if I lived in the Twin Cities."