Screenshot by CNET

Looking to help jump-start a new era in annotating Web text, leading venture capital firm Andreessen Horowitz today said that it's investing $15 million in RapGenius, a startup that enables such annotations.

RapGenius was founded on the idea that rap lyrics needed explanation. And given that Andreessen Horowitz partner Ben Horowitz is a well-known rap devotee, there's an obvious hook that would attract the VC firm to help fund the startup.

"Given that RapGenius is a Web site where people explain rap lyrics, and given that my partner Ben is a noted rap fanatic, your first reaction might be, 'That Horowitz guy has completely lost his mind,'" wrote Marc Andreessen in a release about the funding. "I, on the other hand, find rap every bit as comprehensible as ancient Mesopotamian. That's why I'm writing this...not him."

Andreessen explained that while RapGenius is already well known for helping to decipher hip-hop lyrics and the like, and that the company has a top-tier team, it's the startup's "much bigger idea and...much broader mission" that warranted $15 million of Andreessen Horowitz's money. The idea, he said, is that RapGenius wants to "generalize out to many other areas of text [and to] annotate the world, [to] be the knowledge about the knowledge."

"There's music in other genres and other languages," read the funding announcement, "but what about other categories? Poetry, literature, the Bible, political speeches, legal texts, science papers. And those are just the start. We think the community will continue to expand beyond rap into all culture."

Andreessen concluded his thoughts by explaining that one thing RapGenius does that particularly piqued his interest was offer Web text annotation, something he'd been trying to make happen since he co-built the very first Web browser, Mosaic. "It seemed obvious to us that users would want to annotate all text on the Web -- our idea was that each Web page would be a launchpad for insight and debate about its own contents."

He explained that he and his partner, Eric Bina, built such a system but couldn't make it work for the general public, leading them so shelve it. "I often wonder how the Internet would have turned out differently if users had been able to annotate everything," Andreessen wrote, "to add new layers of knowledge to all knowledge, on and on, ad infinitum. And so, 20 years later, RapGenius finally gives us the opportunity to find out. It's an ambitious mission, and one we are proud to get behind."