This is a pretty straight forward cover by Weezer. A young fan had been begging them on social media for some time to cover "Africa" by Toto, so they decided to cover "Rosanna" instead, in what has to be one of the best troll jobs on a fan ever. They do a solid job on it, but again, it's pretty straight forward, they didn't add much to it.
And, if you're a Weezer fan, they'll be playing with the Pixies at Jiffy Lube Live on July 22nd.