The art of dissecting hip-hop lyrics just got a $15 million vote of confidence from Silicon Valley venture capital firm Andreessen Horowitz.
The firm, whose co-founder Marc Andreessen helped build Mosaic as one of the first Web browsers nearly 20 years ago, on Wednesday announced it has invested $15 million in Rap Genius, a site dedicated to analyzing hip-hop lyrics -- or, as they put it, "critiquing rap as poetry."
The New York-based startup was founded in 2009 by Mahbod Moghadam, Ilan Zechory and Tom Lehman.
Andreessen's venture partner, Ben Horowitz, is a hip-hop fan, which partly explains the Menlo Park, Calif., firm's interest in Rap Genius. The site lets users and rappers write blurbs that explain the meaning of song lyrics, which can range from the philosophical to the banal.
Kanye West's "No Church in the Wild," for example, has this line: "Is Pious pious because God loves pious?" A click on the lyric explains it as a reference to a question posed by Socrates on the nature of religious piety.
Many of the contributors are "verified" rap artists, including Nas, 50 Cent, Mac Miller, Danny Brown, Raekwon, Lupe Fiasco, Kendrick Lamar, RZA, Big Krit and 2 Chainz.
But, as with the site's content, there are other layers to the investment besides rap trivia. Horowitz told Billboard.biz that Rap Genius' approach to Internet content is the main attraction.
"The first thing to understand about Rap Genius that it is the knowledge about the knowledge," Horowitz said. "It's the annotation of the Internet."
In other words, Rap Genius' engine allows its users to lay down context, giving the lyrics additional crowd-sourced intelligence, similar to what Wikipedia does with its community of editors (albeit in a non-profit environment).
Marc Andreessen, in a post explaining his firm's investment  (buried within the list of songs on the site's homepage - and annotated, natch) referenced his desire back in 1993 to build such a feature into Mosaic, which eventually became Netscape. They dropped the idea because the compute power required to track annotations at the time was prohibitive.
"I often wonder how the Internet would have turned out differently if users had been able to annotate everything - to add new layers of knowledge to all knowledge, on and on, ad infinitum," Andreessen wrote wistfully (the annotation says, "Reddit seems to be a good example of when giving the community the ability to 'annotate,' or rather comment on everything, goes bad. Good Annotations Gone Bad," and has a gif of a nuclear bomb exploding). "And so, 20 years later, Rap Genius finally gives us the opportunity to find out."
The investment is intended to fund the company's extension into other topics on the Web, Horowitz said. Exactly how the site will make money is unclear, but Andreessen Horowitz has faith in its popularity, relevance and promise for the future.
"We think what they do is just fundamentally important," Horowitz said. "Anything that's generated a huge audience has become hugely important. Yahoo, AOL, Twitter, Facebook were impossible to monetize. But if you get a lot of people to use it, then monetization becomes not that hard."