Thanks to the comments we've found the guy!
Barcelona awesome Bass Player: Gustavo Dalfarra
Laurie, I got news! The dude's name is Gustavo Dalfarra. He is originally from Barcelona, Venezuela, but he is busking the streets of Barcelona, Spain! More of his videos have sprung up on YouTube, so I was able to find out! The piece's name on this video is "My art is Bass". For more check out
Barcelona awesome Bass Player: Gustavo Dalfarra