As Facebook’s IPO continues to make headlines around the world, one of its key partners, Spotify, is being tipped for a monster funding round that would value the streaming music service at $4bn. The New York Times has the speculation, suggesting that Spotify is looking to raise around $220m, with Goldman Sachs chipping in $100m of that, and other VC firms in discussions to come on board. The funding would give Spotify further runway to build its business, following a $100m round in February 2011 that valued the company at $1bn. New funds would be an important buffer in any new licensing negotiations with music rightsholders, as well as being used to continue scaling Spotify’s business and developing its service. The company is not commenting on the speculation, for now.