Rap Genius gets $15M from Andreessen Horowitz to annotate the entire web

If you think of Rap Genius as just a site for trading notes about song lyrics, a $15 million investment from top-tier VC Andreessen Horowitz may sound a little odd (Ben Horowitz’s love of rap notwithstanding). But if you think about it as a social network organized around all kinds of text online, it starts to make sense.

Launched in 2009 by three friends who met as undergrads at Yale, Williamsburg, NY-based Rap Genius started as a site where fans could crowd-source explanations of rap lyrics by annotating online text. Over the past few years, it’s grown to include millions of music fans around the world. But it’s also started to attract communities interested in annotating non-music-related text, from The Great Gatsby to the State of the Union address to Plessy v. Ferguson Supreme Court decision.

In an annotated (of course) announcement about the Rap Genius funding, Marc Andreessen said the startup’s broader mission is to “Generalize out to many other categories of text … annotate the world … be the knowledge about the knowledge… create the Internet Talmud.”

Rap Genius is about more than rap

With the new cash, the founders say they plan to not only annotate the world, but to create a social network out of it.

“Facebook makes sense as a social network because it’s based on where people went to college. But I think it makes more sense to build a social network around text – be it religious or literary – that people unite around,” said co-founder Mahbod Moghadam.

In his post, Andreessen also mentioned another reason —  which he said might even be the “real reason” — why his company was so interested in Rap Genius: it has the potential to annotate text across the Web, not just documents on its site.

“A big part of it is we think this is a way of creating historical documents that are going to live forever,” said co-founder Ilan Zechory.  “It’s a new layer of Internet culture.”

As the site grows, co-founder Tom Lehman said Rap Genius could release Javascript or browser plugins that would let publishers and readers annotate documents across the Web.  While it wouldn’t necessarily replace some of what comments currently do, he said, it could enable people to comment directly inline and allow a community to really co-create content.

Andreessen noted that when he and Eric Bina first built Mosaic, they initially built a “group annotation” feature directly into the browser but later dropped it because their implementation required a server to host all of the annotation.

“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,” he wrote. “And so, 20 years later, Rap Genius finally gives us the opportunity to find out.”